docker-compose config - bind mount /run/service_logs/ in Agent container (#1236)

This mounts the service_logs directory at /run/service_logs for the purpose
of testing the journald input. It is a workaround but an upstream bug.

Closes #1235

Author: andrewkroh

internal/stack/_static/docker-compose-stack.yml.tmpl

@@ -137,6 +137,10 @@ services:
     - type: bind
       source: ../../../tmp/service_logs/
       target: /tmp/service_logs/
+    # Mount service_logs under /run too as a testing workaround for the journald input (see elastic-package#1235).
+    - type: bind
+      source: ../../../tmp/service_logs/
+      target: /run/service_logs/
 
   elastic-agent_is_ready:
     image: tianon/true