Account for failed underlay builds

if we don't happen to clean the underlay
when we keep the underlay from the docker image

Copy logic to overlay for consistency in behavior

.circleci/config.yml

@@ -61,7 +61,7 @@ references:
       name: Build Underlay
       command: |
         cd $ROS_WS
-        if [ -d install ]
+        if [ -d install ] && [ ! -f build_failed ]
         then
             echo "Skipping Underlay Build"
         else
@@ -72,6 +72,7 @@ references:
                 -DCMAKE_BUILD_TYPE=$CMAKE_BUILD_TYPE \
                 -DCMAKE_C_COMPILER_LAUNCHER=ccache \
                 -DCMAKE_CXX_COMPILER_LAUNCHER=ccache
+            rm -f build_failed
         fi
   save_underlay_cache: &save_underlay_cache
     save_cache:
@@ -114,7 +115,7 @@ references:
     run:
       name: Build Overlay
       command: |
-        if [ -d install ]
+        if [ -d install ] && [ ! -f build_failed ]
         then
             echo "Skipping Overlay Build"
         else
@@ -126,6 +127,7 @@ references:
                 -DCMAKE_C_COMPILER_LAUNCHER=ccache \
                 -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
                 -DCOVERAGE_ENABLED=$COVERAGE_ENABLED
+            rm -f build_failed
         fi
   save_ccache: &save_ccache
     save_cache: