Use system/audio to/from string converters in TypeConverter

Use of system functions eliminates the need for listing all enum
values in TypeConverter tables.

Slight changes in the converting functions:

1. 'channelMaskFromString' function now also accepts indexed
   masks.
2. Fixed UB in 'formatFromString' function.
3. Removed 'deviceFromString' function, use
   'DeviceConverter::fromString' instead.

Replaced direct includes of 'system/audio-base.h' with
includes of 'system/audio.h'.

Bug: 142480271
Test: m
Test: atest libmedia_helper_tests
Change-Id: Ia0e725026be80621bdc797299e63e134419b2b3d
diff --git a/media/libmediahelper/TEST_MAPPING b/media/libmediahelper/TEST_MAPPING
new file mode 100644
index 0000000..f9594bd
--- /dev/null
+++ b/media/libmediahelper/TEST_MAPPING
@@ -0,0 +1,7 @@
+{
+  "presubmit": [
+    {
+      "name": "libmedia_helper_tests"
+    }
+  ]
+}