Add api for cts test to ignore plmn list from storage

Bug: 415139661
Test: make
Flag: EXEMPT bugfix
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:5ad9e39e17de307d62e5044189e50cb635954957)
Merged-In: I1b72121e6170741d363af2d6b26db7840ae9298d
Change-Id: I1b72121e6170741d363af2d6b26db7840ae9298d
1 file changed