audio policy: correct force use touch sound delay

Do not apply the special delay added in setForceUse() multiple times.
This delay was meant to be applied only once to avoid truncating touch
sounds but is actually used multiple times when updating routes on all
output streams, thus lengthening the call audio path switch time
unnecessarily.

Bug: 163537547
Test: manual call routing test
Change-Id: I6fe15d4ed9b1f37452921585e9f7684637e8a30b