Construct profiles instead of remotely starting them

Each profile was exposed as a service that was interacted
with in two ways asynchronously:
- startService: by the Bluetooth app, calling into ActivityManager
  to start a service inside the Bluetooth app itself.
- bindService: by the bluetooth_manager to retrieve the binder
  of this service.

Bluetooth was making an asynchronous call to ActivityManager from
the main thread of its process to start a Service on the main
thread of its process.
This forces a lot of things to be passed as a global variable, as
the creation of the service was externaly managed, which comes with
all the issues associated with global variables.

The flow for the framework to retrieve the binder of a service
was 3rd party app -> system_server (bluetooth manager then activity
manager) -> Bluetooth app. This is unnecessarily complex and is
replaced by this CL to just 3rd party app -> Bluetooth app.

Also all is synchronous now, simplifying some tests and making the
lifecycle easier and removing some races like:
- https://r.android.com/1626228
- https://r.android.com/2810743



A lot of things can be simplified as follow-up thanks to this:
- Removing most global variables of the Bluetooth app.
- Easier and static startup of profiles.

Co-authored-by: David Duarte <licorne@google.com>
Bug: 291815510
Bug: 305741984
Test: atest BluetoothInstrumentationTest
Flag: EXEMPT, Manifest flagging is not available and this change
  is unsafe to do if we don't remove the service entries from the
  manifest
Change-Id: I83a38e1d67de95d8717b5f866868b740e364335d