Add 'audio/mp3' to android.mime.types

MimeTypeMap.getSingleton().getExtensionFromMimeType() returns null since
MimeTypeMap doesn't have 'audio/mp3'. It makes
FileUtils#buildUniqueFile() returns a wrong file. For example, when
mimetype is 'audio/mp3' and filename is test.mp3 which already exists,
it returns test.mp3 (1).

Bug: 205774136
Test: atest FrameworksCoreTests:android.os.FileUtilsTest
Test: atest CtsMimeMapTestCases
Change-Id: I201a7955c735fe99813b5a99692525ace7b0f5fe

core/tests/coretests/src/android/os/FileUtilsTest.java

@@ -58,10 +58,10 @@ import android.provider.DocumentsContract.Document;
 import androidx.test.InstrumentationRegistry;
 import androidx.test.runner.AndroidJUnit4;
 
-import libcore.io.Streams;
-
 import com.google.android.collect.Sets;
 
+import libcore.io.Streams;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -477,6 +477,14 @@ public class FileUtilsTest {
         new File(mTarget, "test (1).jpg").createNewFile();
         assertNameEquals("test (2).jpg",
                 FileUtils.buildUniqueFile(mTarget, "image/jpeg", "test.jpg"));
+
+        assertNameEquals("test.mp3", FileUtils.buildUniqueFile(mTarget, "audio/mp3", "test.mp3"));
+        new File(mTarget, "test.mp3").createNewFile();
+        assertNameEquals("test (1).mp3",
+                FileUtils.buildUniqueFile(mTarget, "audio/mp3", "test.mp3"));
+        new File(mTarget, "test (1).mp3").createNewFile();
+        assertNameEquals("test (2).mp3",
+                FileUtils.buildUniqueFile(mTarget, "audio/mp3", "test.mp3"));
     }
 
     @Test

mime/java-res/android.mime.types

@@ -86,6 +86,7 @@
 ?audio/x-matroska mka
 ?audio/x-pn-realaudio ra
 ?audio/x-mpeg mp3
+?audio/mp3 mp3
 
 ?image/bmp bmp
 ?image/gif gif