RFR: 8312535: MidiSystem.getSoundbank() throws unexpected SecurityException

[Sergey Bylokhov]

* The doPrivileged block is added to fix SecurityException
 * The usage of the property moved to static, now the "change" of the property at runtime will not affect the code

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Commit messages:
 - Update GetSoundBankSecurityException.java
 - Update JARSoundbankReader.java
 - update bugid
 - rename test
 - Update JARSoundbankReader.java
 - test

Changes: https://git.openjdk.org/jdk/pull/14986/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14986&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8312535
  Stats: 66 lines in 3 files changed: 59 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/14986.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14986/head:pull/14986

PR: https://git.openjdk.org/jdk/pull/14986