Remove translation of Metadata's media ID.

Metadata's media ID isn't meant to be shared with user but
to identify and compare medias so its value shouldn't be
translated.

Adding static defaults for values used in default Metadata.

Tag: #feature
Test: atest MetadataTest
Bug: 281065893
Change-Id: I0035256daaa4bd3476dca68181ce9a3b27cbe8d5