MBB: Queue broadcasts in CMI & CMM

Queue per-ClientModeManager broadcasts in BroadcastQueue
instead of sending them directly.

Upon primary ClientModeManager change, send fake disconnect
broadcasts for the previous primary for backwards
compatibility, since apps only expect a single active
STA at a time.

Bug: 175839153
Test: atest FrameworksWifiTests
Test: Trigger Make-Before-Break flow, ensure Settings displays
      correct Wifi connection state (as Settings listens to
      these broadcasts).
Change-Id: I0024ee6026c34ea9c6b1f236229d5eb3fb16e294
11 files changed