chore(build): fix the pre-release versioning

Author: jamesdaniels

tools/build.sh

@@ -5,7 +5,7 @@ yarn
 if test $TAG_NAME; then
     export VERSION=$TAG_NAME
 else
-    export VERSION=$(npm version | head -n 1 |  sed "s/^.*: '\([^']*\).*/\1/")-canary.$SHORT_SHA
+    export VERSION=$(npm version | sed -n "s/. '@angular\/fire': '\(.*\)',/\1/p")-canary.$SHORT_SHA
 fi
 
 echo $VERSION &&