Add default input dispatching timeout constant

To use the same number consistently in java and native, add
IInputConstants interface where we will store the constants.

Bug: 161009325
Test: atest inputflinger_tests
Change-Id: I10f45547b1161e3768a134b38bf40d77a3a82f09
diff --git a/libs/input/android/os/IInputConstants.aidl b/libs/input/android/os/IInputConstants.aidl
new file mode 100644
index 0000000..82c220f
--- /dev/null
+++ b/libs/input/android/os/IInputConstants.aidl
@@ -0,0 +1,24 @@
+/**
+ * Copyright (c) 2020, The Android Open Source Project
+ *
+ * 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
+ *
+ *     http://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.
+ */
+
+package android.os;
+
+
+/** @hide */
+interface IInputConstants
+{
+    const int DEFAULT_DISPATCHING_TIMEOUT_MILLIS = 5000; // 5 seconds
+}