Fix/suppress vts-testcase/fuzz google-explicit-constructor warnings

* Add explicit to conversion constructors/operators

Bug: 28341362
Test: make with WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=-*,google-explicit-constructor
Change-Id: I3b829de5451e05ebb24c1d534265b378001a5d5a
2 files changed