Bug 1727577 - Improve no-topobjdir experience in Android Studio. r=nalexander

Differential Revision: https://phabricator.services.mozilla.com/D123649

settings.gradle

@@ -21,7 +21,14 @@ proc.waitFor()
 
 // Only show the output if something went wrong.
 if (proc.exitValue() != 0) {
-    throw new GradleException("Process '${commandLine}' finished with non-zero exit value ${proc.exitValue()}:\n\nstdout:\n${standardOutput.toString()}\n\nstderr:\n${standardError.toString()}")
+    logger.info("Error running ./mach environment: \n\n"
+        + "Process '${commandLine}' finished with non-zero exit value ${proc.exitValue()}:\n\n"
+        + "stdout:\n"
+        + "${standardOutput.toString()}\n\n"
+        + "stderr:\n"
+        + "${standardError.toString()}")
+    throw new StopExecutionException(
+            "Could not run ./mach environment. Try running ./mach build first.")
 }
 
 import groovy.json.JsonSlurper