[android-porting] How to specify a custom defconfig file in Android 10 Kernel compilation

I wanted to enable certain kernel features and in my Android 10 build for Pixel 3. I downloaded and built the correct msm kernel and successfully flashed it on the Pixel. To build the kernel I'm using the build/build.sh from the kernel source. I tried adding a custom defconfig file in

[android-porting] Vendor manifest.xml not detected

I'm trying to port the AOSP master branch to my device. I stuck at the following error: [ 5% 210/3944] build out/target/product/a5y17lte/obj/PACKAGING/ check_vintf_all_intermediates/check_vintf_vendor_log FAILED: out/target/product/a5y17lte/obj/PACKAGING/