ci(workflows): fix BBG setup path in build workflow

Update the working directory path and security/Kconfig path for BBG setup to ensure correct file modifications during the build process.

.github/workflows/build.yml

@@ -267,11 +267,11 @@ jobs:
 
       - name: Add BBG
         run: |
-          cd "$CONFIG/common"
+          cd "$CONFIG"
           echo "Adding BBG..."
           wget -O- https://github.com/vc-teahouse/Baseband-guard/raw/main/setup.sh | bash
           echo "CONFIG_BBG=y" >> arch/arm64/configs/gki_defconfig
-          sed -i '/^config LSM$/,/^help$/{ /^[[:space:]]*default/ { /baseband_guard/! s/landlock/landlock,baseband_guard/ } }' security/Kconfig
+          sed -i '/^config LSM$/,/^help$/{ /^[[:space:]]*default/ { /baseband_guard/! s/landlock/landlock,baseband_guard/ } }' common/security/Kconfig
           sed -i '/^obj-\$$(CONFIG_BBG) += baseband_guard.o/i # Include kernel config symbols (safe point)\n-include $(srctree)/include/config/auto.conf' Baseband_guard/Makefile
 
       - name: Apply Module Check Bypass