Rename confusing function name for is_robolectric_module

"is_robolectric_module()" checks if the module class is "ROBOLECTRIC".
It can only determine the module is a Legacy Robolectric module.

But this function is easy to misunderstand that this is used to
determine whether this module is a Robolectric test.

Test: m atest && atest-dev --host atest_unittests
Bug: 272391193
Change-Id: I8a19bac9074d15e7e7fe836b2c907b14ca4497df
4 files changed