Use the basename of file_contexts from the info dict.

Changes in [1] break the backward compatibility of the OTA scripts. Fix
the issue by extracting the file basename from the info dict in
META/misc_info.txt.

[1] commit d3a803e6680e86f7b4960d51ab0b620728b793ca

Bug: 23620049
Change-Id: I40a5625bbe0beb295f34b2328906a4a4283fe59b
1 file changed