Use assertEqual instead of assertEquals

Fixes the following failure:

```
fastbuild/bin/tools/bundletool/bundletool_test.runfiles/_main/tools/bundletool/bundletool_test.py", line 146, in _assert_zip_contains
    self.assertEquals(
    ^^^^^^^^^^^^^^^^^
AttributeError: 'BundlerTest' object has no attribute 'assertEquals'. Did you mean: 'assertEqual'?
```

tools/bundletool/bundletool_test.py

@@ -139,11 +139,11 @@ def _assert_zip_contains(self, zip_file, entry, executable=False,
             'Expected %r not to be executable, but it was' % entry)
 
       if compressed:
-        self.assertEquals(
+        self.assertEqual(
             zipfile.ZIP_DEFLATED, zipinfo.compress_type,
             'Expected %r to be compressed, but it was not' % entry)
       else:
-        self.assertEquals(
+        self.assertEqual(
             zipfile.ZIP_STORED, zipinfo.compress_type,
             'Expected %r not to be compressed, but it was' % entry)
     except KeyError: