Audio Policy: Use cached values for getSurroundFormats()

Do not re-open outputs for dynamic parameter resolution.
APM opens outputs for dynamic parameters in checkOutputsForDevice.

Remove 'Manual' word the from dump of surround formats,
as 'mSurroundFormats' is also filled out in 'Auto' mode.

Test: manual using Surround Sound Settings panel
Change-Id: I55870ca7c021e80565722fd1d3ab1553a753a6b6