Update board-info.txt generation method

Bug: 80490116

Update makefile to remove direct shell call to generate the
board-info.txt file.

Test: Manually verify the build passed and board-info.txt generated
contains correct info

Change-Id: Iae10d6d301f9f22668c8cef57ee0f286225c8046

AndroidBoard.mk

@@ -0,0 +1,17 @@
+#
+# Copyright 2018 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.
+#
+
+-include vendor/google_devices/taimen/proprietary/AndroidBoardVendor.mk