use PhoneConstants.PHONE_KEY instead of PHONE_ID

PhoneConstants.PHONE_KEY is already defined.
So change from hard-code PHONE_ID to PhoneConstants.PHONE_KEY

Test: builds
Change-Id: I32dbc1ddbb394be9531f126cb8668a830f798928
Signed-off-by: Sanghee Kim <haya93@samsung.com>