Fix flaky testSetAllowedNetworkTypesForReason

Race condition when adopt and drop using different permission thread when performing setNetworkType and getNetworkType

Fix: 396561050
Test: atest --rerun-until-failure 100 -c android.telephony.cts.TelephonyManagerTest#testSetAllowedNetworkTypesForReason
Test: 100 successful run on the original flaky ROM: https://android-build.corp.google.com/builds/abtd/run/L81000030010487026
Flag: TEST_ONLY

Change-Id: I92f788c1a15df26c31e59e6979fdbca0823ff60a