Audio Policy Engine: remove recurrent warning in getDevicesForStrategyInt()

The legacy routing strategy STRATEGY_PATCH is reserved for internal use
when creating software audio patches and should never be passed to
getDevicesForStrategyInt() to get an output device.
Fixed call sites where this should happen.
Did not getDevicesForStrategyInt() because this method is supposed to
always return a valid device.

Test: basic manual audio regression tests
Flag: EXEMPT, bug fix.
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:b0d986eaf3507b1f4e231d1ab11cc1901ae34cf5)
Merged-In: Ibd3998b461468bc52e0b23711a7aa97e621b1f5b
Change-Id: Ibd3998b461468bc52e0b23711a7aa97e621b1f5b