audio flinger: rename Bluetooth latency mode APIs

Rename APIs controlling Bluetooth variable latency
after API review suggestions.

Bug: 257922898
Test: make
Change-Id: I517ad9c6aef14975c9e0a1a2703d1b17d638ea0e
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 247c609..1f0f13a 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -1102,7 +1102,7 @@
                     return INVALID_OPERATION;
                 }
 
-    virtual     status_t setBluetoothLatencyModesEnabled(bool enabled);
+    virtual     status_t setBluetoothVariableLatencyEnabled(bool enabled);
 
                 void startMelComputation(const sp<audio_utils::MelProcessor>& processor);
                 void stopMelComputation();