Change default Robolectric default source dir

Improve the logic to resolve the source directory used for code
coverage by using the path of the makefile of the module under test.
This allows the Robolectric tests to be placed in any location, while
assuming that the source directories are at $(dirname makefile)/src
or $(dirname makefile)/java

Test: m -j64 RunSettingsLibRoboTests-jacoco
Change-Id: I297fe8f20ecbe3732cc1504ec3881994aed6af05
1 file changed