Added touch grid sensor plugin.

PiperOrigin-RevId: 527512624
Change-Id: I0f316eb6eb2c52472abbec484e5538b66ba2e82e

test/plugin/sensor/CMakeLists.txt

@@ -0,0 +1,21 @@
+# Copyright 2022 DeepMind Technologies Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+mujoco_test(
+  sensor_test
+  PROPERTIES
+  ENVIRONMENT
+  "MUJOCO_PLUGIN_DIR=$<TARGET_FILE_DIR:sensor>"
+)
+target_link_libraries(sensor_test fixture gmock)