RFR: 8284888 : [macos] javax/swing/JInternalFrame/8146321/JInternalFrameIconTest.java failed with "NimbusLookAndFeel] : ERROR: icon and imageIcon not same."

[Prasanta Sadhukhan]

Test used to fail in specific CI macos M1 system owing to miniscule color difference 


x 0 y 0 red1 171 red2 171 green1 174 green2 175 blue1 184 blue2 184
x 0 y 1 red1 172 red2 173 green1 177 green2 177 blue1 185 blue2 185
x 0 y 2 red1 173 red2 174 green1 177 green2 178 blue1 187 blue2 187
x 0 y 6 red1 0 red2 0 green1 1 green2 0 blue1 0 blue2 0
x 0 y 15 red1 1 red2 0 green1 0 green2 0 blue1 0 blue2 0


SInce we already have color-tolerance check present, there is no need of exact color value check.
Also, made the frame undecorated and remove unneeded library being built. 
Several iterations of the test passed in the same system (where it used to fail 4/7) along with other platforms (link in JBS)

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Commit messages:
 - Fix

Changes: https://git.openjdk.java.net/jdk/pull/8380/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8380&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8284888
  Stats: 14 lines in 1 file changed: 4 ins; 3 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8380.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8380/head:pull/8380

PR: https://git.openjdk.java.net/jdk/pull/8380