Improved coverage report instructions.
Improved coverage report instructions.

[Feature]       More detailed per-file coverage report instructions.
[Cause]         N/A
[Solution]      N/A
[Verification]  Follow new instructions.

Change-Id: I75c563e8627f2f2e5aa22329e231f18fc4f1841a

Samsung/vasum,Samsung/vasum,Samsung/vasum,Samsung/vasum