TextOutput log improvement

Add unit tests for log functions
Add support of std::endl
Add back support of char
Add back support of bool
Add back support of String16
Fix a build warning on union initialization

Test: run /data/nativetest(64)/binderTextOutputTest
Bug: 32181382
Change-Id: I4030b142beacc5dcd88a10904710fd6e19f7240c