To make InputMethodPreference support 2 target
reference, CL[1] move the PrimarySwitchPreference
into SettingsLib.
Change all PrimarySwitchPreference reference to
Settingslib one and remove the original one.
[1]: Idea3935d95b8d22b00ca89313e9eb3e979e4aa74
Bug: 197705032
Test: Presubmit
Change-Id: I95d111522344bb7cbdd380382e48fe60a5ebc9a2