build: Override host metadata

reference taken from
https://grapheneos.social/@GrapheneOS/113870255397154703

instead of fixed host number, use a random generated host number that follows google's host number format to bypass revolut's host checks

Change-Id: I72feafd663a551eb0c6c4146d52137ed0dc7456d
Co-authored-by: Terminator-J <terminator_j@hotbutteredmonkey.com>
Signed-off-by: rmp22 <195054967+rmp22@users.noreply.github.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>

build/envsetup.sh

@@ -1012,3 +1012,14 @@ function build_kernel() {
     chmod -x "${target_kernel_dir}/"*
     echo "Kernel build output copied to ${target_kernel_dir}/"
 }
+
+function generate_host_overrides() {
+    export BUILD_USERNAME=android-build
+    HEX=$(openssl rand -hex 8)
+    ALPHA=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 4 | head -n 1)
+    export BUILD_HOSTNAME="r-${HEX}-${ALPHA}"
+    echo "BUILD_USERNAME=$BUILD_USERNAME"
+    echo "BUILD_HOSTNAME=$BUILD_HOSTNAME"
+}
+
+generate_host_overrides