Use full path for LOCAL_INSTRUMENT_SOURCE_DIRS

We get fail from running RunWallPaperPicker2RoboTests-jacoco because Jacoco fail to get the source code path to parse the code coverage.

Test step:
1. tapas RunWallPaperPicker2RoboTests
2. make -j30 dist (Make sure RunWallPaperPicker2RoboTests does not break)
3. make -j30 RunWallPaperPicker2RoboTests-jacoco dist
4. See the coverage report
Bug: 147334774

Change-Id: Ia45981629950d127f5c3f45a67f288d00c83e597
1 file changed