feat(monitoring)!: update the API

BREAKING CHANGE: This release has breaking changes.

#### monitoring:v1
The following keys were added:
- schemas.Dashboard.properties.mosaicLayout.$ref
- schemas.Dashboard.properties.mosaicLayout.description
- schemas.MosaicLayout.description
- schemas.MosaicLayout.id
- schemas.MosaicLayout.properties.columns.description
- schemas.MosaicLayout.properties.columns.format
- schemas.MosaicLayout.properties.columns.type
- schemas.MosaicLayout.properties.tiles.description
- schemas.MosaicLayout.properties.tiles.items.$ref
- schemas.MosaicLayout.properties.tiles.type
- schemas.MosaicLayout.type
- schemas.Tile.description
- schemas.Tile.id
- schemas.Tile.properties.height.description
- schemas.Tile.properties.height.format
- schemas.Tile.properties.height.type
- schemas.Tile.properties.widget.$ref
- schemas.Tile.properties.widget.description
- schemas.Tile.properties.width.description
- schemas.Tile.properties.width.format
- schemas.Tile.properties.width.type
- schemas.Tile.properties.xPos.description
- schemas.Tile.properties.xPos.format
- schemas.Tile.properties.xPos.type
- schemas.Tile.properties.yPos.description
- schemas.Tile.properties.yPos.format
- schemas.Tile.properties.yPos.type
- schemas.Tile.type

#### monitoring:v3
The following keys were deleted:
- schemas.UptimeCheckConfig.properties.selectedRegions.enumDescriptions

The following keys were changed:
- resources.projects.resources.timeSeries.methods.list.parameters.aggregation.alignmentPeriod.description
- resources.services.methods.list.parameters.filter.description
- schemas.Aggregation.properties.alignmentPeriod.description
- schemas.CollectdPayload.properties.values.description
- schemas.CollectdValue.properties.dataSourceName.description
- schemas.Distribution.properties.sumOfSquaredDeviation.description
- schemas.MetricDescriptor.description
- schemas.MetricDescriptor.properties.labels.description
- schemas.MetricDescriptor.properties.type.description
- schemas.MonitoredResourceDescriptor.description
- schemas.MonitoredResourceDescriptor.properties.labels.description
- schemas.MonitoredResourceDescriptor.properties.type.description
- schemas.QueryTimeSeriesRequest.properties.query.description
- schemas.TimeInterval.description

discovery/monitoring-v1.json

@@ -275,7 +275,7 @@
       }
     }
   },
-  "revision": "20200803",
+  "revision": "20200927",
   "rootUrl": "https://monitoring.googleapis.com/",
   "schemas": {
     "Aggregation": {
@@ -480,6 +480,10 @@
           "$ref": "GridLayout",
           "description": "Content is arranged with a basic layout that re-flows a simple list of informational elements like widgets or tiles."
         },
+        "mosaicLayout": {
+          "$ref": "MosaicLayout",
+          "description": "The content is arranged as a grid of tiles, with each content widget occupying one or more grid blocks."
+        },
         "name": {
           "description": "Immutable. The resource name of the dashboard.",
           "type": "string"
@@ -709,6 +713,25 @@
       },
       "type": "object"
     },
+    "MosaicLayout": {
+      "description": "A mosaic layout divides the available space into a grid of blocks, and overlays the grid with tiles. Unlike GridLayout, tiles may span multiple grid blocks and can be placed at arbitrary locations in the grid.",
+      "id": "MosaicLayout",
+      "properties": {
+        "columns": {
+          "description": "The number of columns in the mosaic grid. The number of columns must be between 1 and 12, inclusive.",
+          "format": "int32",
+          "type": "integer"
+        },
+        "tiles": {
+          "description": "The tiles to display.",
+          "items": {
+            "$ref": "Tile"
+          },
+          "type": "array"
+        }
+      },
+      "type": "object"
+    },
     "Option": {
       "description": "A protocol buffer option, which can be attached to a message, field, enumeration, etc.",
       "id": "Option",
@@ -989,6 +1012,37 @@
       },
       "type": "object"
     },
+    "Tile": {
+      "description": "A single tile in the mosaic. The placement and size of the tile are configurable.",
+      "id": "Tile",
+      "properties": {
+        "height": {
+          "description": "The height of the tile, measured in grid blocks. Tiles must have a minimum height of 1.",
+          "format": "int32",
+          "type": "integer"
+        },
+        "widget": {
+          "$ref": "Widget",
+          "description": "The informational widget contained in the tile. For example an XyChart."
+        },
+        "width": {
+          "description": "The width of the tile, measured in grid blocks. Tiles must have a minimum width of 1.",
+          "format": "int32",
+          "type": "integer"
+        },
+        "xPos": {
+          "description": "The zero-indexed position of the tile in grid blocks relative to the left edge of the grid. Tiles must be contained within the specified number of columns. x_pos cannot be negative.",
+          "format": "int32",
+          "type": "integer"
+        },
+        "yPos": {
+          "description": "The zero-indexed position of the tile in grid blocks relative to the top edge of the grid. y_pos cannot be negative.",
+          "format": "int32",
+          "type": "integer"
+        }
+      },
+      "type": "object"
+    },
     "TimeSeriesFilter": {
       "description": "A filter that defines a subset of time series data that is displayed in a widget. Time series data is fetched using the ListTimeSeries (https://cloud.google.com/monitoring/api/ref_v3/rest/v3/projects.timeSeries/list) method.",
       "id": "TimeSeriesFilter",