libaudiohal: implement supportsBluetoothVariableLatency for HIDL

Implement supportsBluetoothVariableLatency for HIDL by way of
getParameters API.

Bug: 287695426
Test: verify that low latency mode is requested when TalkBack is playing
Change-Id: Ibacbdf6cefbcb96b6ac3cfd82b6d26a0e36c8a08
(cherry picked from commit 321b5c9d45a1d15bb289dcd139e43287185dbd36)
diff --git a/media/libaudiohal/impl/DeviceHalAidl.cpp b/media/libaudiohal/impl/DeviceHalAidl.cpp
index 3125e311..de123f4 100644
--- a/media/libaudiohal/impl/DeviceHalAidl.cpp
+++ b/media/libaudiohal/impl/DeviceHalAidl.cpp
@@ -951,7 +951,7 @@
     return mModule->dump(fd, Args(args).args(), args.size());
 }
 
-int32_t DeviceHalAidl::supportsBluetoothVariableLatency(bool* supports) {
+status_t DeviceHalAidl::supportsBluetoothVariableLatency(bool* supports) {
     TIME_CHECK();
     if (!mModule) return NO_INIT;
     if (supports == nullptr) {
diff --git a/media/libaudiohal/impl/DeviceHalAidl.h b/media/libaudiohal/impl/DeviceHalAidl.h
index 37d800b..613eb63 100644
--- a/media/libaudiohal/impl/DeviceHalAidl.h
+++ b/media/libaudiohal/impl/DeviceHalAidl.h
@@ -162,7 +162,7 @@
 
     error::Result<audio_hw_sync_t> getHwAvSync() override;
 
-    int32_t supportsBluetoothVariableLatency(bool* supports __unused) override;
+    status_t supportsBluetoothVariableLatency(bool* supports __unused) override;
 
     status_t getSoundDoseInterface(const std::string& module,
                                    ::ndk::SpAIBinder* soundDoseBinder) override;
diff --git a/media/libaudiohal/impl/DeviceHalHidl.cpp b/media/libaudiohal/impl/DeviceHalHidl.cpp
index 826461f..d043568 100644
--- a/media/libaudiohal/impl/DeviceHalHidl.cpp
+++ b/media/libaudiohal/impl/DeviceHalHidl.cpp
@@ -681,4 +681,26 @@
 }
 #endif
 
+status_t DeviceHalHidl::supportsBluetoothVariableLatency(bool* supports) {
+    if (supports == nullptr) {
+        return BAD_VALUE;
+    }
+    *supports = false;
+
+    String8 reply;
+    status_t status = getParameters(
+            String8(AUDIO_PARAMETER_BT_VARIABLE_LATENCY_SUPPORTED), &reply);
+    if (status != NO_ERROR) {
+        return status;
+    }
+    AudioParameter replyParams(reply);
+    String8 trueOrFalse;
+    status = replyParams.get(
+            String8(AUDIO_PARAMETER_BT_VARIABLE_LATENCY_SUPPORTED), trueOrFalse);
+    if (status != NO_ERROR) {
+        return status;
+    }
+    *supports = trueOrFalse == AudioParameter::valueTrue;
+    return NO_ERROR;
+}
 } // namespace android
diff --git a/media/libaudiohal/impl/DeviceHalHidl.h b/media/libaudiohal/impl/DeviceHalHidl.h
index c5addde..43ec4d7 100644
--- a/media/libaudiohal/impl/DeviceHalHidl.h
+++ b/media/libaudiohal/impl/DeviceHalHidl.h
@@ -125,10 +125,7 @@
         return INVALID_OPERATION;
     }
 
-    int32_t supportsBluetoothVariableLatency(bool* supports __unused) override {
-        // TODO: Implement the HAL query when moving to AIDL HAL.
-        return INVALID_OPERATION;
-    }
+    status_t supportsBluetoothVariableLatency(bool* supports) override;
 
     status_t setConnectedState(const struct audio_port_v7 *port, bool connected) override;