Clear up ALWAYS_REPORTED_SIGNAL_STRENGTH_CHANGED in PIM

Feature "always report signal strength" has been replaced
with the new feature introduced in S release. The ability
to allow system user to request reporting signal strength
when phone is idle is provided by public API with same
perssion protection.

Bug: 177924721
Test: atest PhoneInterfacemanagerTest
Change-Id: Ic7e82b79419e406137c34d9d870e53375ed46968
1 file changed