223c179cd3
When a device is in DSDS mode with multiple SIMs, we show a header on the Network & internet page with a "connectivity overview", with an entry for Wi-Fi (if connected) and each active SIM. The icon for Wi-Fi shows signal strength, but the icons for the active SIMs were just static; this CL fixes that. It introduces a class for listening to signal strength changes on a set of subscriptions, and moves some existing code we had for displaying signal strength (when manually picking networks for GSM) in NetworkOperatorPreference into a utility method that can be shared. Bug: 128855095 Test: make RunSettingsRoboTests Change-Id: I668cafe1e9f9c3651b1f33783c8538ad9c2732b5