Add TEST_MAPPING and Build file for tests

Created Android.bp file to compile keymaster tests and TEST_MAPPING to
run all the tests.

Test: Run TEST_MAPPING file: 'atest --test-mapping tests:presubmit'
      Run only keymaster_tests: 'atest keymaster_tests'
Change-Id: I2ad746c87ee4ef062889dbe7e42a742968bbdafd
7 files changed