Instrument Time output is affected by device locale

### Description
If you change the locale in a test, the "Time:" output printed by an `am instrument` command also changes. Instrumentation Output Parsers are then unable to parse the total instrumentation time.

### Steps to Reproduce
1. Change locale to Arabic
2. Run an instrument command
### Expected Results
Time: 1.23
### Actual Results
Time: ٣٫٦٤١
### AndroidX Test and Android OS Versions
All versions.

I already have a PR open to fix this: #931, I just need a review.

Review PR #931 first, since the issue says the fix is already open and only needs review. Reproduce the locale change to Arabic and run an am instrument command; done means the Time output remains parseable with locale-independent digits and separators.

Written by the indexing model from the issue text.