Use AudioPatch getter method to access handle

The AudioPatch API changed upstream to make the handle a private member
variable.
https://keystone-qcom.googlesource.com/platform/frameworks/av/+/afd4cea46c12f55a7ccd47271314d59d833aa5c0

Bug: 149114520
Change-Id: Ic9092b003b35ed51d640b9349c4dfa2dc3980d79
diff --git a/policy_hal/AudioPolicyManager.cpp b/policy_hal/AudioPolicyManager.cpp
index 8a0295a..6238fa9 100644
--- a/policy_hal/AudioPolicyManager.cpp
+++ b/policy_hal/AudioPolicyManager.cpp
@@ -926,11 +926,11 @@
             updateCallRouting(rxDevices, delayMs);
         } else if (oldState == AUDIO_MODE_IN_CALL) {
             if (mCallRxPatch != 0) {
-                mpClientInterface->releaseAudioPatch(mCallRxPatch->mAfPatchHandle, 0);
+                mpClientInterface->releaseAudioPatch(mCallRxPatch->getAfHandle(), 0);
                 mCallRxPatch.clear();
             }
             if (mCallTxPatch != 0) {
-                mpClientInterface->releaseAudioPatch(mCallTxPatch->mAfPatchHandle, 0);
+                mpClientInterface->releaseAudioPatch(mCallTxPatch->getAfHandle(), 0);
                 mCallTxPatch.clear();
             }
             setOutputDevices(mPrimaryOutput, rxDevices, force, 0);