dashboards: fix vmagent monitoring chart descriptions (#7283)

### Describe Your Changes

Fix vmagent monitoring chart descriptions
### Checklist

The following checks are **mandatory**:

- [x ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).

Signed-off-by: Artem Fetishev <rtm@victoriametrics.com>

dashboards/vm/vmagent.json

@@ -951,7 +951,7 @@
         "type": "victoriametrics-datasource",
         "uid": "$ds"
       },
-      "description": "Shows the persistent queue size of pending samples in bytes >2MB which hasn't been flushed to remote storage yet. \n\nIncreasing of value might be a sign of connectivity issues. In such cases, vmagent starts to flush pending data on disk with attempt to send it later once connection is restored.\n\nRemote write URLs are hidden by default but might be unveiled once `-remoteWrite.showURL` is set to true.\n\nClick on the line and choose Drilldown to show CPU usage per instance.\n",
+      "description": "Shows the persistent queue size of pending samples in bytes >2MB which hasn't been flushed to remote storage yet. \n\nIncreasing of value might be a sign of connectivity issues. In such cases, vmagent starts to flush pending data on disk with attempt to send it later once connection is restored.\n\nRemote write URLs are hidden by default but might be unveiled once `-remoteWrite.showURL` is set to true.\n\nClick on the line and choose Drilldown to show persistent queue size per instance.\n",
       "fieldConfig": {
         "defaults": {
           "color": {
@@ -2834,7 +2834,7 @@
             "type": "victoriametrics-datasource",
             "uid": "$ds"
           },
-          "description": "Shows saturation persistent queue for writes. If the threshold of 0.9sec is reached, then persistent is saturated by more than 90% and vmagent won't be able to keep up with flushing data on disk. In this case, consider to decrease load on the vmagent or improve the disk throughput.",
+          "description": "Shows write saturation of the persistent queue. If the threshold of 0.9sec is reached, then the persistent queue is saturated by more than 90% and vmagent won't be able to keep up with flushing data on disk. In this case, consider to decrease load on the vmagent or improve the disk throughput.",
           "fieldConfig": {
             "defaults": {
               "color": {
@@ -2941,7 +2941,7 @@
             "type": "victoriametrics-datasource",
             "uid": "$ds"
           },
-          "description": "Shows saturation persistent queue for reads. If the threshold of 0.9sec is reached, then persistent is saturated by more than 90% and vmagent won't be able to keep up with reading data from the disk. In this case, consider to decrease load on the vmagent or improve the disk throughput.",
+          "description": "Shows read saturation of the persistent queue. If the threshold of 0.9sec is reached, then the persistent queue is saturated by more than 90% and vmagent won't be able to keep up with reading data from the disk. In this case, consider to decrease load on the vmagent or improve the disk throughput.",
           "fieldConfig": {
             "defaults": {
               "color": {

dashboards/vmagent.json

@@ -950,7 +950,7 @@
         "type": "prometheus",
         "uid": "$ds"
       },
-      "description": "Shows the persistent queue size of pending samples in bytes >2MB which hasn't been flushed to remote storage yet. \n\nIncreasing of value might be a sign of connectivity issues. In such cases, vmagent starts to flush pending data on disk with attempt to send it later once connection is restored.\n\nRemote write URLs are hidden by default but might be unveiled once `-remoteWrite.showURL` is set to true.\n\nClick on the line and choose Drilldown to show CPU usage per instance.\n",
+      "description": "Shows the persistent queue size of pending samples in bytes >2MB which hasn't been flushed to remote storage yet. \n\nIncreasing of value might be a sign of connectivity issues. In such cases, vmagent starts to flush pending data on disk with attempt to send it later once connection is restored.\n\nRemote write URLs are hidden by default but might be unveiled once `-remoteWrite.showURL` is set to true.\n\nClick on the line and choose Drilldown to show the persistent queue size per instance.\n",
       "fieldConfig": {
         "defaults": {
           "color": {
@@ -2833,7 +2833,7 @@
             "type": "prometheus",
             "uid": "$ds"
           },
-          "description": "Shows saturation persistent queue for writes. If the threshold of 0.9sec is reached, then persistent is saturated by more than 90% and vmagent won't be able to keep up with flushing data on disk. In this case, consider to decrease load on the vmagent or improve the disk throughput.",
+          "description": "Shows write saturation of the persistent queue. If the threshold of 0.9sec is reached, then the persistent queue is saturated by more than 90% and vmagent won't be able to keep up with flushing data on disk. In this case, consider to decrease load on the vmagent or improve the disk throughput.",
           "fieldConfig": {
             "defaults": {
               "color": {
@@ -2940,7 +2940,7 @@
             "type": "prometheus",
             "uid": "$ds"
           },
-          "description": "Shows saturation persistent queue for reads. If the threshold of 0.9sec is reached, then persistent is saturated by more than 90% and vmagent won't be able to keep up with reading data from the disk. In this case, consider to decrease load on the vmagent or improve the disk throughput.",
+          "description": "Shows read saturation of the persistent queue. If the threshold of 0.9sec is reached, then the persistent queue is saturated by more than 90% and vmagent won't be able to keep up with reading data from the disk. In this case, consider to decrease load on the vmagent or improve the disk throughput.",
           "fieldConfig": {
             "defaults": {
               "color": {