RFR: 8306838: GetGraphicsTest needs to be headful

[Prasanta Sadhukhan]

Newly added GetGraphicsTest should be headful as it uses a Frame


java.awt.HeadlessException:
No X11 DISPLAY variable was set,
or no headful library support was found,
but this program performed an operation which requires it,

at java.desktop/java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:166)
at java.desktop/java.awt.Window.<init>(Window.java:553)
at java.desktop/java.awt.Frame.<init>(Frame.java:428)
at java.desktop/java.awt.Frame.<init>(Frame.java:393)
at GetGraphicsTest.<init>(GetGraphicsTest.java:35)
at GetGraphicsTest.main(GetGraphicsTest.java:47)

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Commit messages:
 - 8306838: GetGraphicsTest needs to be headful

Changes: https://git.openjdk.org/jdk/pull/13639/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13639&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8306838
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/13639.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13639/head:pull/13639

PR: https://git.openjdk.org/jdk/pull/13639