[8u] RFR: 8191678: [TESTBUG] Add keyword headful in java/awt and javax tests.

[Alex Kashchenko]

Hi,

Please review the backport of JDK-8191678 to 8u:

Bug: https://bugs.openjdk.java.net/browse/JDK-8191678

Original change: https://hg.openjdk.java.net/jdk/jdk/rev/50d61f4b5d1a

8u webrev: https://cr.openjdk.java.net/~akasko/jdk8u/8191678/webrev.00/

This change adds "headful" keyword to a number of client tests. Only a 
single test (FocusTransitionTest) from this patch is present in 8u - 
only changes to it are backported.

Testing: checked that changed test can be selected with "headful" keyword.

-- 
-Alex