init script: Add usergroup write permission to idle_time node.

Set usergroup write permission of idle_time node to enable idle
timeout feature.

Change-Id: If6b0a94e93b5117c4004726d62a346403f7a8ed3
CRs-Fixed: 610823
Merge "Merge "Removing unsupported targets from lunch combo""
Merge "Merge "Merge "Removing unsupported targets from lunch combo"""
Merge "Merge "Removing unsupported targets from lunch combo""
Merge "Merge "Merge "Removing unsupported targets from lunch combo"""
Merge "Merge "Removing unsupported targets from lunch combo""
Merge "Merge "Merge "Removing unsupported targets from lunch combo"""
Merge "Merge "Removing unsupported targets from lunch combo""
Merge "Merge "Merge "Removing unsupported targets from lunch combo"""
Merge "Merge "Removing unsupported targets from lunch combo""
Merge "Merge "Merge "Removing unsupported targets from lunch combo"""
Merge "Merge "Removing unsupported targets from lunch combo""
Merge "Merge "Merge "Removing unsupported targets from lunch combo"""
Merge "Merge "Removing unsupported targets from lunch combo""
Merge "Merge "Merge "Removing unsupported targets from lunch combo"""
Merge "Merge "Removing unsupported targets from lunch combo""
Merge "Merge "Merge "Removing unsupported targets from lunch combo"""
Merge "Merge "Removing unsupported targets from lunch combo""
Merge "Merge "Merge "Removing unsupported targets from lunch combo"""
Merge "Merge "Removing unsupported targets from lunch combo""