Revert "healthd: charger: Modify charger unplug shutdown time to 1s"

This fixes hammerhead off mode charging and shouldn't bother
other devices.

This reverts commit 2e8628e9685c62b2cf881ba9f5aef406713f0175.

Change-Id: Ibe6477884d22e37981a3c5549a3a72aae1963152