AndroidRpiOverlay, AndroidTvRpiOverlay, BluetoothRpiOverlay,
CarServiceRpiOverlay, SettingsRpiOverlay, and SystemUIRpiOverlay were
identical in pawlet_rpi4 and pawlet_rpi5. Consolidate them here so
they have a single source of truth.
Device-specific overlays (SettingsProviderRpiOverlay,
SettingsProviderTvRpiOverlay, WifiRpiOverlay) stay per-device because
they contain device-name and SSID strings that differ between rpi4/rpi5.
device/pawlet/rpi is already in PRODUCT_SOONG_NAMESPACES via
vendor/pawlet/config/rpi_common.mk, so no makefile changes are needed.
oxmc