Fix/suppress hwui google-explicit-constructor warnings

* Add explicit to conversion constructors/operators
* Use NOLINT or NOLINTNEXTLINE to suppress warnings on intended converters

Bug: 28341362
Test: make with WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=-*,google-explicit-constructor
Change-Id: I8c6ebb99679b0a71251024d70a13f8164e67db5e
6 files changed