Improve make android test targets

[tobrun]

We are going to expand the make commands related to Android testing. We currently expose a make android test that runs our unit tests. We are now thinking of spliting up this command into multiple make commands:

• make android-core-test
• make android-ui-test
• make android-unit-test
• make android test (contains all above)

We also should look into making it possible to pass in arguments to be able to run one testcase instead of the whole testsuite.

[tobrun]

Not required for next release, taking it of the milestone.

[tobrun]

Obsolete with #6697