Use safe_union correctly

As described in source.android.com/devices/architecture/hidl/safe_union
value must be assigned through generated getter, rather than assigning it directly.

Test: vts-tradefed run vts -m VtsHalBluetoothAudioV2_1TargetTest
Sponsor: jpawlowski@
Bug: 150670922
Change-Id: Iefc7ee98163ec2b3387fc01c3d69c1dcd15e94bc
diff --git a/bluetooth/audio/2.1/default/BluetoothAudioProvider.cpp b/bluetooth/audio/2.1/default/BluetoothAudioProvider.cpp
index 092038b..73fe06c 100644
--- a/bluetooth/audio/2.1/default/BluetoothAudioProvider.cpp
+++ b/bluetooth/audio/2.1/default/BluetoothAudioProvider.cpp
@@ -57,14 +57,14 @@
 
   if (audioConfig.getDiscriminator() ==
       V2_0::AudioConfiguration::hidl_discriminator::pcmConfig) {
-    audioConfig_2_1.pcmConfig() = {
+    audioConfig_2_1.pcmConfig({
         .sampleRate =
             static_cast<SampleRate>(audioConfig.pcmConfig().sampleRate),
         .channelMode = audioConfig.pcmConfig().channelMode,
         .bitsPerSample = audioConfig.pcmConfig().bitsPerSample,
-        .dataIntervalUs = 0};
+        .dataIntervalUs = 0});
   } else {
-    audioConfig_2_1.codecConfig() = audioConfig.codecConfig();
+    audioConfig_2_1.codecConfig(audioConfig.codecConfig());
   }
 
   return startSession_2_1(hostIf, audioConfig_2_1, _hidl_cb);