battery: Remove low battery state notifying

battery: Remove low battery state notifying

Below dbus method is removed from commit 55a6ef08adcc1e75439d31cbdd9d4dce72fabe7d.
METHOD_LOW_NOTI_ON          "BatteryLowNotiOn"
METHOD_LOW_NOTI_UPDATE      "BatteryLowNotiUpdate"
METHOD_LOW_NOTI_OFF         "BatteryLowNotiOff"
METHOD_CRITICAL_NOTI_ON     "BatteryCriticalNotiOn"
METHOD_CRITICAL_NOTI_UPDATE "BatteryCriticalNotiUpdate"
METHOD_CRITICAL_NOTI_OFF    "BatteryCriticalNotiOff"

After removed that dbus methods from system-popup, deviced code was not removed.
It is calling functions that does not exist.
Thus, meaningless dbus method calls are removed.

Change-Id: I8a1de226ca9e644e0786d8140d1013a7173dc77c
Signed-off-by: Yunhee Seo <yuni.seo@samsung.com>