Instead of using summary for verifer, change the security setting
summary to a static text.
Bug: 36889582
Test: make RunSettingsRoboTests
Change-Id: Ia3e2c7c595f403965751bacf2239c70070408e49
Each time we refresh the security preference page, get the current
summary text from "On the lock screen" and populate to Lock screen
preferences summary.
Bug: 36540633
Test: make RunSettingsRoboTests
Change-Id: I317e3892b35b30981b62f7b7aee9cfdacd04a3ed
Update the summary text to show the number of active trust agent.
Bug: 36540633
Test: make RunSettingsRoboTests
Change-Id: I6627564a8356022c89694c84cfd47e875a0916b1
Bug: 31002801
Test: make RunSettingsRoboTests
The Security summary is implemented to show the same summary as the
package verifier injected tile if one exists.
Change-Id: I0a2f163a801a7b07fd5363b302c451aca8d389b0
