Android Studio: Fix module generation for all

Accidentally reversed logic in last CL so that by default every
build.gradle file was generated. Consolidated logic in args.all.

Bug: 620034
Change-Id: I5efe128150f688296abb1f835b3cbe7eba58f3ae
Reviewed-on: https://chromium-review.googlesource.com/1048398
Commit-Queue: Eric Stevenson <estevenson@chromium.org>
Reviewed-by: Eric Stevenson <estevenson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556797}
diff --git a/build/android/gradle/generate_gradle.py b/build/android/gradle/generate_gradle.py
index 3061a4b..cb05d60 100755
--- a/build/android/gradle/generate_gradle.py
+++ b/build/android/gradle/generate_gradle.py
@@ -854,16 +854,15 @@
   project_entries = []
   # When only one entry will be generated we want it to have a valid
   # build.gradle file with its own AndroidManifest.
-  add_all_module = not args.split_projects and len(entries) > 1
   for entry in entries:
     data = _GenerateGradleFile(
         entry, generator, build_vars, source_properties, jinja_processor)
-    if data and add_all_module:
+    if data and not args.all:
         project_entries.append((entry.ProjectName(), entry.GradleSubdir()))
         _WriteFile(
             os.path.join(generator.EntryOutputDir(entry), _GRADLE_BUILD_FILE),
             data)
-  if add_all_module:
+  if args.all:
     project_entries.append((_MODULE_ALL, _MODULE_ALL))
     _GenerateModuleAll(
         _gradle_output_dir, generator, build_vars, source_properties,