Problem: When the Blackview BV900 Pro has been restarted, the earphone volume will always go to mute (zero)
Environment: Build number BV9000Pro_Blackview-V1.1_20171215
Severity: High
Steps to reproduce
1. Restart the phone
Expected results: Phone should automatically retain its last earphone volume setting
Actual results: Phone earphone volume is mute (zero)