Add PreferStylusOverTouchBlocker and handle multiple devices

We removed PreferStylusOverTouchBlocker previously in order to avoid a
crash. In this CL, we are adding it back in, and handling the case of
input device having "SOURCE_STYLUS", but reporting "finger" tool type.

If there's a stylus event with one of the pointers labeled as 'finger',
let's assume that the device supports simultaneous touch and stylus. For
this situation, simply disable PreferStylusOverTouchBlocker going
forward for these devices, and pass through any events coming from there.

Currently, this happens on emulator. In their touch driver, they
configure stylus properties as well as touch properties, but most of the
events that they send are TOOL_TYPE_FINGER. Previously, this triggered a
crash in PreferStylusOverTouchBlocker.

Bug: 222531989
Test: atest inputflinger_tests
Change-Id: Ifbb08858a4dfebc95c30ca19d6e68533855db7e4
diff --git a/libs/input/PrintTools.cpp b/libs/input/PrintTools.cpp
new file mode 100644
index 0000000..5d6ae4e
--- /dev/null
+++ b/libs/input/PrintTools.cpp
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+#define LOG_TAG "PrintTools"
+
+#include <input/PrintTools.h>
+
+namespace android {
+
+const char* toString(bool value) {
+    return value ? "true" : "false";
+}
+
+} // namespace android