Add utilities to get the Android backtrace

* Added getBacktraceInfo(), which returns the backtrace information
  from the ANGLE code, including the addresses and the symbols if
  possible

  * Returns the data in an instance of the new class BacktraceInfo.

  * In order to access this function, backtrace_utils.h has been
    included in vk_utils.h

* New GN flag to make use of this feature:

  * angle_enable_unwind_backtrace_support

    * Current only available on Android (debug mode)

  * If the flag is disabled, getBacktraceInfo() returns an empty
    object.

* Added functions in util/ (per platform) to print the BacktraceInfo
  data.

  * Example of usage:
      angle::printBacktraceInfo(angle::getBacktraceInfo());

* Minor edit: Moved cstdint from android_util.cpp to its header.

Bug: b/258475923
Change-Id: I6115462a1a2845d40c7cafc14ce52df09ecdcf34
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3995843
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Charlie Lao <cclao@google.com>
Commit-Queue: Amirali Abdolrashidi <abdolrashidi@google.com>

util/linux/linux_backtrace.cpp

@@ -0,0 +1,19 @@
+//
+// Copyright 2022 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// linux_backtrace.cpp:
+//   Implements functions to output the backtrace from the ANGLE code during execution on Linux.
+//
+
+#include "common/backtrace_utils.h"
+
+namespace angle
+{
+
+// It is possible to refactor the implementation of printing the backtrace information from the
+// PrintStackBacktrace() function.
+void printBacktraceInfo(BacktraceInfo backtraceInfo) {}
+
+}  // namespace angle