Flip --incompatible_check_sharding_support

RELNOTES[INC]: `--incompatible_check_sharding_support` is enabled by default. Sharded tests with test runners that do not properly advertise support for test sharding will fail. Refer to bazelbuild#18339 for migration advice.

Author: fmeum

src/main/java/com/google/devtools/build/lib/analysis/test/TestConfiguration.java

@@ -293,7 +293,7 @@ public static class TestOptions extends FragmentOptions {
 
     @Option(
         name = "incompatible_check_sharding_support",
-        defaultValue = "false",
+        defaultValue = "true",
         documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
         metadataTags = {OptionMetadataTag.INCOMPATIBLE_CHANGE},
         effectTags = {OptionEffectTag.UNKNOWN},

src/test/py/bazel/test_wrapper_test.py

@@ -70,6 +70,7 @@ def _CreateMockWorkspace(self):
         'bat_test(',
         '    name = "sharded_test",',
         '    content = [',
+        '        "copy /b %TEST_SHARD_STATUS_FILE% +,,"',
         '        "@echo STATUS=%TEST_SHARD_STATUS_FILE%",',
         '        "@echo INDEX=%TEST_SHARD_INDEX% TOTAL=%TEST_TOTAL_SHARDS%",',
         '    ],',

src/test/shell/bazel/bazel_test_test.sh

@@ -540,9 +540,10 @@ EOF
 function test_xml_fallback_for_sharded_test() {
   mkdir -p dir
 
-  cat <<EOF > dir/test.sh
+  cat <<'EOF' > dir/test.sh
 #!/bin/sh
-exit \$((TEST_SHARD_INDEX == 1))
+touch "$TEST_SHARD_STATUS_FILE"
+exit $((TEST_SHARD_INDEX == 1))
 EOF
 
   chmod +x dir/test.sh