Cloud sql documentation changes (#15953)

Author: aditikumarii-google

mmv1/third_party/terraform/website/docs/r/sql_database_instance.html.markdown

@@ -270,6 +270,46 @@ resource "google_sql_database_instance" "main" {
 }
 ```
 
+### Cloud SQL Instance created with backupdr_backup
+~> **NOTE:** For restoring from a backupdr_backup, note that the backup must be in active state. List down the backups using `google_backup_dr_backup`. Replace `backupdr_backup_full_path` with the backup name.
+
+```hcl
+resource "google_sql_database_instance" "instance" {
+  name             = "main-instance"
+  database_version = "MYSQL_8_0"
+  settings {
+    tier    = "db-f1-micro"
+    backup_configuration {
+      enabled = true
+      binary_log_enabled = true
+    }
+    backupdr_backup = "backupdr_backup_full_path"
+  }
+}
+```
+
+### Cloud SQL Instance created using point_in_time_restore
+~> **NOTE:** Replace `backupdr_datasource` with the full datasource path, `time_stamp` should be in the format of `YYYY-MM-DDTHH:MM:SSZ`.
+
+```hcl
+resource "google_sql_database_instance" "instance" {
+  name             = "main-instance"
+  database_version = "MYSQL_8_0"
+  settings {
+    tier    = "db-f1-micro"
+    backup_configuration {
+      enabled = true
+      binary_log_enabled = true
+    }
+  }
+  point_in_time_restore_context {
+   datasource      = "backupdr_datasource"
+   target_instance = "target_instance_name"
+   point_in_time   = "time_stamp"
+ }
+}
+```
+
 ## Argument Reference
 
 The following arguments are supported: