Make NetworkAgent#sendNetworkInfo public again

Changing this method to private broke OEM code that would link
directly against the non-public methods of the module. This
should not be allowed, and we have changes in the works to
disallow this, but in the mean time we can't afford to break
devices in the field.

Test: will have to see how it behaves in the lab on relevant devices
Flag: EXEMPT bugfix
Bug: 406489362
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:f7e102081d578454ed9eea8616927fbf5100a6ce)
Merged-In: Ie6c1ebb04e49317fdda34ff3dd522cd9d4677556
Change-Id: Ie6c1ebb04e49317fdda34ff3dd522cd9d4677556
1 file changed