Revert "Use TelephonyManager#isEmergencyNumber() instead"

Revert submission 1453740-replace_with_isEmergencyNumber

Reason for revert: <Telephony service may not up while calling this, causing failures.>

This also cherry picks ag/14444738

Change-Id: I5aa71917ce1b2abcdfcf78b8988d128982a6b3ec
Bug: 132703886
Bug: 181062609
Bug: 187720309
Merged-In: I5df03a61f55f863e17594aa3239433a5048a4890