Make it easier to add new build architectures

by making the build file generator script (mostly) architecture independent.

Bug: 269761242
Test: build x64 and arm64 locally
Change-Id: I76ea4bc0ba5e8e5c152b93cb1ad7a385c796adae

android_tools/generate_android_bp.sh

@@ -9,12 +9,7 @@ fi
 
 DIR=$(dirname $0)
 
-PYTHONHASHSEED=31 "${DIR}"/generate_bp.py \
-        "${DIR}"/project_x64.json \
-        "${DIR}"/project_x86.json \
-        "${DIR}"/project_arm64.json \
-        "${DIR}"/project_arm.json \
-        >"${DIR}"/../Android.bp
+PYTHONHASHSEED=31 "${DIR}"/generate_bp.py "$DIR" >"${DIR}/../Android.bp"
 
-bpfmt -w "${DIR}"/../Android.bp
+bpfmt -w "${DIR}/../Android.bp"