zenfone9: Build Omx media and libstagefright from source

Change-Id: Iabf1c02b29f745cf0d3eb615d5e1f3102da26428
diff --git a/BoardConfig.mk b/BoardConfig.mk
index dc55ed7..df0697e 100755
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -203,6 +203,7 @@
 BOARD_ROOT_EXTRA_FOLDERS += ADF APD asdf batinfo
 
 # Platform
+QCOM_HARDWARE_VARIANT := sm8450
 TARGET_BOARD_PLATFORM_GPU := qcom-adreno660
 TARGET_USES_KERNEL_PLATFORM := true