Merge pull request #30912 from mwl/fix/aws-multicluster-per-region

Automatic merge from submit-queue

Added INSTANCE_PREFIX to project hash to avoid S3 bucket clash

**What this PR does / why we need it**:
Fixes an issue where if you run multiple k8s clusters in same region S3 resources are being overwritten and therefore node bootstrapping stalls, i.e. when using Auto scaling.

**Special notes for your reviewer**:
By adding the `INSTANCE_PREFIX` to the project hash in the S3 bucket the bucket will not be overwritten.

**Release note**:
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cluster/aws/util.sh

@@ -609,9 +609,9 @@ function upload-server-tars() {
       local project_hash=
       local key=$(aws configure get aws_access_key_id)
       if which md5 > /dev/null 2>&1; then
-        project_hash=$(md5 -q -s "${USER} ${key}")
+        project_hash=$(md5 -q -s "${USER} ${key} ${INSTANCE_PREFIX}")
       else
-        project_hash=$(echo -n "${USER} ${key}" | md5sum | awk '{ print $1 }')
+        project_hash=$(echo -n "${USER} ${key} ${INSTANCE_PREFIX}" | md5sum | awk '{ print $1 }')
       fi
       AWS_S3_BUCKET="kubernetes-staging-${project_hash}"
   fi