javax.sound tests should not set java.home system property

Summary

Default configuration of JavaSound cannot be customized.

Problem

There is no way to provide location of "sound.properties", which is by default located in the jdk/conf folder. For the similar purpose for logging the next property is used: "java.util.logging.config.file" which points to "logging.properties"

Solution

The new optional "javax.sound.config.file" system property can be added, which specified default location of the "sound.properties".

Specification

 src/java.desktop/share/classes/javax/sound/midi/MidiSystem.java

  * Properties can be used to specify default MIDI devices. Both system
  * properties and a properties file are considered. The "sound.properties"
  * properties file is read from an implementation-specific location (typically
- * it is the {@code conf} directory in the Java installation directory). If a
+ * it is the {@code conf} directory in the Java installation directory).
+ * The optional "javax.sound.config.file" system property can be used to specify
+ * the properties file that will be read as the initial configuration. If a
  * property exists both as a system property and in the properties file, the

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src/java.desktop/share/classes/javax/sound/sampled/AudioSystem.java

  * Both system properties and a properties file are considered. The
  * "sound.properties" properties file is read from an implementation-specific
  * location (typically it is the {@code conf} directory in the Java installation
- * directory). If a property exists both as a system property and in the
+ * directory). The optional "javax.sound.config.file" system property can be
+ * used to specify the properties file that will be read as the initial
+ * configuration. If a property exists both as a system property and in the
  * properties file, the system property takes precedence. If none is specified,

Reference for convenience http://cr.openjdk.java.net/~serb/8201279/webrev.02/