docs: Update cpu_utilization_percent limit

docs: Remove the limitation of all clusters in a CMEK instance must use the same key

PiperOrigin-RevId: 438385300

google/bigtable/admin/v2/instance.proto

@@ -118,7 +118,8 @@ message Instance {
 message AutoscalingTargets {
   // The cpu utilization that the Autoscaler should be trying to achieve.
   // This number is on a scale from 0 (no utilization) to
-  // 100 (total utilization).
+  // 100 (total utilization), and is limited between 10 and 80, otherwise it
+  // will return INVALID_ARGUMENT error.
   int32 cpu_utilization_percent = 2;
 }
 
@@ -165,7 +166,6 @@ message Cluster {
     //  `cloudkms.cryptoKeyEncrypterDecrypter` role on the CMEK key.
     //  2) Only regional keys can be used and the region of the CMEK key must
     //  match the region of the cluster.
-    // 3) All clusters within an instance must use the same CMEK key.
     string kms_key_name = 1 [(google.api.resource_reference) = {
       type: "cloudkms.googleapis.com/CryptoKey"
     }];