WifiManager: Remove async channel usage

Changes:
a) Migrate existing async channel methods to tracked binder calls.
b) Migrate existing async channel responses to tracked binder callbacks.
c) Deprecate WifiManager.disable() (Use public WifiManager.disableNetwork()
instead). Don't see any external users of this API.
d) Removed unnecessary RssiPacketInfo class (only the total pkt count is
necessary in the public API, so remove this class and only pass the
total count in the callback).

Bug: 130039719
Test: atest android.net.wifi
Test: Manual tests
a) Able to connect to networks from settings.
b) Able to remove network from setttings.

Change-Id: Ie82a9fce2f9e32e48a2da77477893427863fb460