dump state string vs state number

for media.metrics codec errors, we want to dump the string
(e.g., "RUNNING") instead of a numeric value "4". This is easier
to consume AND is robust in the face of any changes to the
numeric values of the states.

Bug: 70525617
Test: manual
Change-Id: Ic0c8a9b6e77f33dad0a9738077355287e882d6a0