Refactor the PatchCommandThread for reuse.

Extract the CommandThread into PatchCommandThread and make it reusable
for other components interested in PatchPanel changes.

Test: manual
Bug: 252776298
Change-Id: I16db5341543328b4a84be238aa7c1b5804dfe7c9
diff --git a/services/audioflinger/Android.bp b/services/audioflinger/Android.bp
index 87c67bd..2549f7c 100644
--- a/services/audioflinger/Android.bp
+++ b/services/audioflinger/Android.bp
@@ -44,6 +44,7 @@
         "FastThreadDumpState.cpp",
         "FastThreadState.cpp",
         "NBAIO_Tee.cpp",
+        "PatchCommandThread.cpp",
         "PatchPanel.cpp",
         "PropertyUtils.cpp",
         "SpdifStreamOut.cpp",