Use setFlags to disable two line toggle flag in tests.

disableFlags for Flags.FLAG_ENABLED_TWOLINE_TOGGLE

bug: 316027081
Test: presubmit/gantry/manual
BubbleTextViewTest: https://screenshot.googleplex.com/8zFHWbwCFyxTTHC
Flag: com.android.launcher3.enable_twoline_toggle DEVELOPMENT
Change-Id: I530126de6ac63395acd2d176935e6f6f9759d4c3