Revert "Promote metric settings in compute region autoscaler to GA" (#10095) (#7035)

This reverts commit c3ce700765fbc4b3dc9896da767194b8eda9a13d.

[upstream:5d86b613cda684877c2f0ad98b4d4e524e6aa89a]

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/10095.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+compute: promoted `metric.single_instance_assignment` and `metric.filter` for `google_compute_region_autoscaler` to GA (revert)
+```

website/docs/r/compute_region_autoscaler.html.markdown

@@ -172,7 +172,7 @@ The following arguments are supported:
   Defines operating mode for this policy.
 
 * `scale_down_control` -
-  (Optional)
+  (Optional, [Beta](https://terraform.io/docs/providers/google/guides/provider_versions.html))
   Defines scale down controls to reduce the risk of response latency
   and outages due to abrupt scale-in events
   Structure is [documented below](#nested_scale_down_control).
@@ -287,7 +287,7 @@ The following arguments are supported:
   The metric must have a value type of INT64 or DOUBLE.
 
 * `single_instance_assignment` -
-  (Optional)
+  (Optional, [Beta](https://terraform.io/docs/providers/google/guides/provider_versions.html))
   If scaling is based on a per-group metric value that represents the
   total amount of work to be done or resource usage, set this value to
   an amount assigned for a single instance of the scaled group.
@@ -321,7 +321,7 @@ The following arguments are supported:
   Possible values are: `GAUGE`, `DELTA_PER_SECOND`, `DELTA_PER_MINUTE`.
 
 * `filter` -
-  (Optional)
+  (Optional, [Beta](https://terraform.io/docs/providers/google/guides/provider_versions.html))
   A filter string to be used as the filter string for
   a Stackdriver Monitoring TimeSeries.list API call.
   This filter is used to select a specific TimeSeries for