Make auto Wi-Fi summary text consistent with feature availability.

"Turn Wi-Fi on automatically" feature is disabled when airplane mode or
battery saver mode is enabled, when Wi-Fi scanning is disabled, or when
network recommendations are disabled / scorer unset. This change
captures these negative cases in the summary text.

Bug: 65085700
Test: make ROBOTEST_FILTER=WifiWakeupPreferenceControllerTest
RunSettingsRoboTests -j40
Change-Id: I2f2d22b5bef3ad03a28d34e79a27e6545cac557f