Improve Logic for Detecting Carrier Load Complete

-Add empty PersistableBundles to allow CarrierConfigLoader to
 operate as though loads are all completed after bind/load times
 out OR fails from either the carrier service package OR the system
 default package.

-Fix the case where carrier/system default keys hadn't loaded but
 a bundle would report that CONFIG_APPLIED=true if there are test
 overrides; this could cause the system to proceed during SIM change
 in test scenarios despite the complete configs not having been
 loaded.

Bug: 176523196
Test: atest TeleServiceTests // and additional manual test
Change-Id: Id6434de52f7b1c69a0ceda037c5a96d29c1c7641
1 file changed