Convert mask types from uint32_t to enum type

This applies to the following types:

- audio_gain_mode_t;
- audio_flags_mask_t;
- audio_channel_representation_t;
- audio_channel_mask_t;
- audio_devices_t.

Enum types are distinct thus proper overloading on the type
is possible in C++. Also, assignments to enum types are
less prone to errors.

Bug: 169889714
Test: basic audio functionality
Change-Id: I07e96ae99724f38fe0b40194f4feab7ff68418e7
diff --git a/audio/core/all-versions/default/Conversions.cpp b/audio/core/all-versions/default/Conversions.cpp
index eddff55..0b6ad80 100644
--- a/audio/core/all-versions/default/Conversions.cpp
+++ b/audio/core/all-versions/default/Conversions.cpp
@@ -31,7 +31,7 @@
     // HAL assumes that the address is NUL-terminated.
     char halAddress[AUDIO_DEVICE_MAX_ADDRESS_LEN];
     memset(halAddress, 0, sizeof(halAddress));
-    uint32_t halDevice = static_cast<uint32_t>(address.device);
+    audio_devices_t halDevice = static_cast<audio_devices_t>(address.device);
     if (getAudioDeviceOutAllA2dpSet().count(halDevice) > 0 ||
         halDevice == AUDIO_DEVICE_IN_BLUETOOTH_A2DP) {
         snprintf(halAddress, sizeof(halAddress), "%02X:%02X:%02X:%02X:%02X:%02X",