Support sharding robolectric tests

Explicitly pass the list of tests as LOCAL_ROBOTEST_FILES, and
support sharding the list of tests into multiple test runners.

Also filter out BaseRobolectricTest.java, which covers the only
use of LOCAL_ROBOTEST_FILES in Android.mk files.

Bug: 133878985
Test: m RunSettingsLibRoboTests runs the same number of tests before and after
Test: m RunSettingsLibRoboTests runs the same number of tests when sharded
Change-Id: Id85ffe03c98e722303eaa6def17812ed2244c6a6
Merged-In: Id85ffe03c98e722303eaa6def17812ed2244c6a6
diff --git a/Android.bp b/Android.bp
index 614e71f..fff17ef 100644
--- a/Android.bp
+++ b/Android.bp
@@ -296,6 +296,7 @@
         "java/jdeps_test.go",
         "java/kotlin_test.go",
         "java/plugin_test.go",
+        "java/robolectric_test.go",
         "java/sdk_test.go",
     ],
     pluginFor: ["soong_build"],