Increase clone retry backoff to 30s in build_tflite.sh

Use a 30-second initial sleep and 30-second linear increment when retrying dependency clones in build_tflite.sh.

buildbot/build_tflite.sh

diff --git a/buildbot/build_tflite.sh b/buildbot/build_tflite.sh
index 738a0c4..199e4a9 100755
--- a/buildbot/build_tflite.sh
+++ b/buildbot/build_tflite.sh
@@ -47,7 +47,7 @@
   local repo="$1"
   local tag="$2"
   local dest="$3"
-  local sleep_seconds=10
+  local sleep_seconds=30
   for i in $(seq 1 5); do
     rm -rf "${dest}"
     if git clone --filter=tree:0 --no-checkout "${repo}" "${dest}" && \
@@ -55,7 +55,7 @@
       return 0
     fi
     sleep "${sleep_seconds}"
-    sleep_seconds=$((sleep_seconds + 10))
+    sleep_seconds=$((sleep_seconds + 30))
   done
   return 1
 }