Added decoding of truncated AAPT string lengths.

AAPT incorrectly writes a truncated string length when the string size
exceeded the maximum possible encode length value (0x7FFF). To decode a
truncated length, this change iterates through length values that end
in the encode length bits. Strings that exceed the maximum encode length
are not placed into StringPools in AAPT2.

Test: Successfully ran broken apps from the duplicates of the bugs
provided and created tests
Bug: 69320870

Change-Id: I99dd9b63e91ac250f81d5dfc26b7c0e6276ae162