ci: fix upload-symbols harder

The symbols server expect a specific layout for the archive, and
fetch-content extracts our symbols archive one directory deeper than I
expected.

taskcluster/kinds/upload-symbols/kind.yml

@@ -42,7 +42,7 @@ tasks:
     run:
       using: run-commands
       commands:
-        - [automation/upload_android_symbols.sh, /builds/worker/fetches/crashreporter-symbols]
+        - [automation/upload_android_symbols.sh, /builds/worker/fetches/crashreporter-symbols/crashreporter-symbols]
       dummy-secrets:
           by-level:
               '3': []