Merge pull request #11027 from huchengtw-moz/system/bug_888821_ua_profile_configuration_based_on_mcc_mnc

Bug 888821 - B2G MMS: UA profile configuration based on MNC and MCC. r=archurcc(cherry picked from commit 4ec7c428f6a63a44f888ea6f6ade0385c89ae305)

Conflicts:
	apps/system/js/operator_variant/operator_variant.js
Merge remote-tracking branch 'huchengtw-moz/system/Bug_888821-v1-train' into v1-train