Bug 983079 - [MADAI][Browser] @2.25x assets update for Browser
Bug 980701 - Make sure we do not try to place more than two calls

We cannot open more than two lines, and mozTelephony is not able yet to
tell us that we are doing this. So we do a check ourself for now, and
bug 990472 should fix it at mozTelephony level.
Merge pull request #18021 from steveck-chung/Browser-2.25X

Bug 983079 - [MADAI][Browser] @2.25x assets update for Browser r=benfrancis
Merge pull request #17982 from lissyx/bug980701

Bug 980701 - Make sure we do not try to place more than two calls r=etienne
Revert "Revert (manually revert) "Bug 933035 - [B2G][System][Lockscreen] The"

This reverts commit 86ff94b32e369a925b79ae16ced141c1ac36fc0e.

After confirmed this backout didn't help the bug,
I now reland the code back, and to see if it can solve the other bug
may cause by it (Bug 993281)
Bug 983459 - Notify of no voicemail number when tapping voicemail notification

If we don't have any voicemail number (on the SIM card nor configured in
Settings), when the user is tapping on the voicemail notification,
nothing will happen. This is confusing, so we implement a modal dialog
to notify of the lack of voicemail number configured, and we add a link
to the Settings app to configure it.