Remove the Bazel provided default cxxopt -std=c++0x and replace it with -std=c++14 when testing with GCC 5.
Remove the Bazel provided default cxxopt -std=c++0x and replace it
with -std=c++14 when testing with GCC 5.

PiperOrigin-RevId: 458502826
Change-Id: I83637a222b5c0a54e55d93ce7fdbc878af27b250

google/googletest,google/googletest,google/googletest,google/googletest