Make TimeDetectorService more aware of origin

Make TimeDetectorService more aware of a time signal's origin by making
the time signal from telephony less generic.

When TimeDetectorService was written it was assumed that the TimeSignal
could be generic and there would just be a String source identifier to
indicate origin.

With multiple SIMs / phones on a device it makes sense to keep track of
the originating phone of the signal so that the time detector service
could implement stickiness if it wanted. This would avoid a device
alternating back and forth between two signals and help with debugging.

As new signals are added, new "suggestXxxxTime()" methods will be added
to TimeDetectorService. That is the point at which the strategy for
ranking different sources can be decided. e.g. should NTP always rank
higher than NITZ?

The main change here is that TimeSignal is renamed to
PhoneTimeSuggestion to indicate it's only for use by signals from
telephony, sourceId has been removed and it has been given a phoneId
instead. Extra free-form metadata (mDebugInfo) has been added to assist
with logging / debugging.

Bug:140712361
Test: atest android.app.timedetector
Test: atest com.android.server.timedetector
Change-Id: I5305c34516e5f4e254309193183f00e054801a46