Restricting UserBuild from presistent carrierConfig Override Bug: 441823943 Flag: EXEMPT Bugfix Test: manually verified Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:e129f3e192cc2082f5ea46676be6c882b2fe742e Merged-In: I915b1ffa30418bdb5df553057680e44b1b18af06 Change-Id: I915b1ffa30418bdb5df553057680e44b1b18af06