projects: lkft-android: include: Add defaults to metadata

[stylesen]

Default to 'unknown' when a particular metadata parameter is unavailable.

[liuyq]

@stylesen thanks for the change! LGTM

[liuyq]

Hi, @roxell @bhcopeland
when you are online could you please help check and merge if no issues there.

[bhcopeland]

I would go with null values when the value is unknown, then defining the word unknown. But apart from that LGTM

[stylesen]

I would go with null values when the value is unknown, then defining the word unknown. But apart from that LGTM

@bhcopeland this is the same followed in lkft devices as seen here - https://github.com/Linaro/lava-test-plans/blob/master/lava_test_plans/projects/lkft/include/metadata.jinja2

[bhcopeland]

@stylesen fair enough, lets push this through. Null should be set there, but lets keep it matched.