[automerger skipped] Merge "getNetworkCountryIso API should return empty when signal is lost." am: e534e108 am: aac214f1 am: cff0619c am: 3b4a4928 -s ours

am skip reason: Change-Id Ia90b0210a6430bab6a2c4a6fa424e100c1e83e4d with SHA-1 558a738b is in history

Original change: https://android-review.googlesource.com/c/platform/frameworks/opt/telephony/+/1582534

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ib0db370c0c34a44034c78578cc0280244d09e8dc