Switch the locale header in the png files from Locale.toString() to
Locale.toLanguageTag(). For example, en_US --> en-us and sr__#Latn
--> sr-Latn. Also clean up recovery a bit to expect the new locale
format.
Bug: 35215015
Test: sr-Latn shows correctly under graphic tests && recovery tests pass
Change-Id: Ic62bab7756cdc6e5f98f26076f7c2dd046f811db
match_locale() will return false for empty locale string in the PNG
file. Also add a manual test to validate if a PNG file is qualified to
use under recovery.
Bug: 34054052
Test: recovery_manual_test catches invalid PNG files successfully & Locale_test passed
Change-Id: Id7e2136e1d8abf20da15825aa7901effbced8b03
matches_locale was expecting input locale string to have at most one
underscore; as a result "zh_CN_#Hans" ignores "zh_CN" and matches into
"zh". Fix the match function and add unit tests.
Bug: 27837319
Change-Id: I4e8a66f91cae6ac2a46b6bf21f670d5ea564c7c8
