Add support for XMP tags.

These Extensible Metadata Platform (XMP) tags contain XML data which
is used to communicate rich metadata information beyond EXIF.

TIFF: Tag 700
JPEG: Application segment 1 (0xFFE1) with segment header
"http://ns.adobe.com/xap/1.0/\x00"

Bug: 120791890
Test: atest cts/tests/tests/media/src/android/media/cts/ExifInterfaceTest.java
Change-Id: Iacccbf9b516b3204d99a760eaeb19a41554c3f97