Improve JUnit4 compatibility on Flicker

Create a test factory to produce multiple flicker tests with different configurations and use a test rule instead of inheritance to execute the tests

Moreover, flicker tests now are displayed multiple times in the results log:
- for the transition itself (i.e., test run worked);
 -for the assertions (if the trace passed or failed the assertions)
 - for flaky assertions (if not ignoring FlakyTests)

Test: atest FlickerTests
Change-Id: I19939b934dc2bda61d8cd44ddfb043be73a08fc5