Fix Stub override when argument is already defined

Mockito does not always support stub override.
It fail when a a method has 2 stub with different argument matcher
Ex:
  doReturn(x).when(y).method(any(Foo.class));
  Foo foo = Foo();
  doReturn(x).when(y).method(eq(foo)); <-- sub-match of above

But the following "should" be ok
  Foo foo = Foo();
  doReturn(x).when(y).method(eq(foo));
  Bar bar = Bar();
  doReturn(x).when(y).method(eq(bar)); <-- same scope match as above

Test: atest BluetoothInstrumentationTests
Bug: 256291144
Change-Id: Ie84e4bbe1ed3c479adc2a194972ba67e34839f50