Translate paths before leaving app sandbox.

When sending the ACTION_MEDIA_SCANNER_SCAN_FILE broadcast, an app
provides a raw filesystem path, which might be inside of their
sandbox.

Once the broadcast is delivered, we don't know where it came from,
so we need to translate the path before leaving the app process.

Bug: 117909601
Test: atest cts/tests/tests/provider/src/android/provider/cts/MediaStore*
Change-Id: Ibddd72a2d85e1f6541e0d6209e539fe6b5c4bde0