Preset selector should preview preset

[Florian Doyon]

Expected Behaviour:

• opening the dialog keeps track of the currently used saved preset or unsaved eq curve
• the player should always play whichever preset is currently selected in the right spinner
• pressing OK dismisses the dialog
• pressing Cancel dismisses the dialog then reinstalls the previously saved preset / eq curve

[acet]

Looking at this

[acet]

https://bitbucket.org/myNoise/mynoise.android/pull-requests/2/