Android: Clarify "build-bundle-apks" argument usage.

--sdk-version isn't currently used, but it's a bit misleading that it
implies --minimal.

This CL changes app_bundle_utils.GenerateBundleApks to enforce minimal
to be passed for --sdk-version to work.

Bug: 996362
Change-Id: I808273d92f73cd50015101da551df04d53ad6d2b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1779008Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Eric Stevenson <estevenson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#692199}

build/android/apk_operations.py

@@ -1525,8 +1525,7 @@ class _BuildBundleApks(_Command):
         help='Build .apks archive that targets the bundle\'s minSdkVersion and '
         'contains only english splits. It still contains optional splits.')
     group.add_argument(
-        '--sdk-version',
-        help='Implies --minimal. The sdkVersion to build the .apks for.')
+        '--sdk-version', help='The sdkVersion to build the .apks for.')
     group.add_argument(
         '--build-mode',
         choices=app_bundle_utils.BUILD_APKS_MODES,
@@ -1540,7 +1539,7 @@ class _BuildBundleApks(_Command):
     _GenerateBundleApks(
         self.bundle_generation_info,
         self.args.output_apks,
-        minimal=self.args.sdk_version is not None or self.args.minimal,
+        minimal=self.args.minimal,
         minimal_sdk_version=self.args.sdk_version,
         mode=self.args.build_mode)
 

build/android/pylib/utils/app_bundle_utils.py

@@ -72,6 +72,10 @@ def GenerateBundleApks(bundle_path,
       or "system_compressed".
   """
   device_spec = None
+  if minimal_sdk_version:
+    assert minimal or system_image_locales, (
+        'minimal_sdk_version is only used when minimal or system_image_locales '
+        'is specified')
   if minimal:
     # Measure with one language split installed. Use Hindi because it is
     # popular. resource_size.py looks for splits/base-hi.apk.