Performance Optimizations for CarrierPrivilegesTracker

-Reduce the memory usage of CPT by only holding the hash of
 the SHA digests (a hash of hashes) in memory for each
 package. This also moves away from using hex strings in
 favor of doing byte-based comparisons, which saves the
 conversion from byte->ascii for storage and back to byte
 during the comparison in UiccPrivilegesRule. Memory saving
 should be... (Old_Size - New_Size) * Num_Phones * Num Packages

 Old_Size = (SHA1_len + SHA256_len) * Bytes_Per_AsciiHex_Byte
 - Bytes_Per_Int * 2 =
 = (20 + 32) * (2 * 2)  = 208 bytes

 New_Size = 2 * Bytes_Per_Int = 16

 Num_Packages = ~350

 (208 - 16) * 350 * 2 * 1  = 132KB / installed user

-This will also speed up searches in the event that there
 is no carrier package at the slight cost of increasing the
 lookup cost in the event that there is one or more carrier
 packages because a full comparison requires a binder call.
 Because the circumstances that cause a lookup are pretty
 rare, this feels like a very minimal regression to me.

By combining into a single cache that could operate across
multiple phones, we could further simplify; however, I believe
that would come with additional complexity that is no longer
worthwhile given that the total impact should now be only a few
KB per instance.

Bug: 162182054
Test: atest CarrierPrivilegesTrackerTest; #note: refactor-only
Flag: EXEMPT refactor
Change-Id: I9e817a2a2853891a1ee56447157db40cb808ab53