[BUG] audio: misalignement of native/java AudioAttributes

Native audio attributes are initialized with a default source,
whereas JAVA AudioAttributes are initialized with an INVALID source.
It leads to equality failure, thus preventing to identify the
right strategy / volume group.
This CL fixes this issue by forcing the source to invalid for
AudioAttributesGroups, only used for product strategies, thus dedicated
to playback use cases.

Test: AudioVolumeGroupTest
Bug: 248287204
Bug: 238058094

Signed-off-by: François Gaffie <francois.gaffie@renault.com>
Change-Id: Ie40576421aff595112740821ea002bc70354f512