Empty triangle displayed for radio signal but calls & data work

TelephonyRegistry: when default sub id is requested set isLegacyApp to
true so when ACTION_DEFAULT_SUBSCRIPTION_CHANGED is received the
TelephonyRegistry.Record.subId will be updated.

SubInfoRecord: Add SubInfoRecord toString for easier debugging

SubscriptionManager: Add putPHoneIdAndSubIdExtra(intent, phoneId, subId)
as this allows explicit setup of phoneId and subId and does not rely on
a phone's subId being set.

Bug: 15669560
Change-Id: I645ddb35b964b08dcb46f881c9d02b932d128950