Update android_sdk system_image support to include 27 and 28.

RELNOTES: None.
PiperOrigin-RevId: 203169316
diff --git a/tools/android/android_sdk_repository_template.bzl b/tools/android/android_sdk_repository_template.bzl
index 216f718..fd7630f 100644
--- a/tools/android/android_sdk_repository_template.bzl
+++ b/tools/android/android_sdk_repository_template.bzl
@@ -291,7 +291,7 @@
     system_images = [
         (tag, str(api), arch)
         for tag in ["android", "google"]
-        for api in [10] + range(15, 20) + range(21, 27)
+        for api in [10] + range(15, 20) + range(21, 29)
         for arch in ("x86", "arm")
     ]
     tv_images = [