Convert to Android.bp build file

Support is equivalent to Android.mk file built with
TARGET_BUILD_VARIANT of 'user'.
diff --git a/Android.bp b/Android.bp
new file mode 100644
index 0000000..a2dc388
--- /dev/null
+++ b/Android.bp
@@ -0,0 +1,43 @@
+//
+// ANT Stack
+//
+// Copyright 2019 Garmin Canada
+//
+// 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.
+//
+
+android_app {
+    name: "AntHalService",
+
+    //
+    // ANT java system service
+    //
+
+    srcs: [
+        "src/**/*.java",
+        "src/com/dsi/ant/server/IAntHal.aidl",
+        "src/com/dsi/ant/server/IAntHalCallback.aidl",
+    ],
+
+    static_libs: ["com.dsi.ant-V1.0-java"],
+
+    optimize: {
+        // Remove all verbose and debug logging when building release
+	proguard_flags_files: ["proguard.flags", "proguard.nolog.flags"], 
+    },
+
+    certificate: "platform",
+
+    platform_apis: true,
+
+}
diff --git a/Android.mk b/Android.mk
deleted file mode 100644
index 060fd24..0000000
--- a/Android.mk
+++ /dev/null
@@ -1,44 +0,0 @@
-#
-# ANT Stack
-#
-# Copyright 2011 Dynastream Innovations
-#
-# 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.
-#
-
-LOCAL_PATH := $(call my-dir)
-include $(CLEAR_VARS)
-
-#
-# ANT java system service
-#
-
-LOCAL_SRC_FILES := \
-    $(call all-java-files-under, src) \
-    src/com/dsi/ant/server/IAntHal.aidl \
-    src/com/dsi/ant/server/IAntHalCallback.aidl
-
-LOCAL_STATIC_JAVA_LIBRARIES := \
-    com.dsi.ant-V1.0-java-static
-
-LOCAL_PROGUARD_FLAG_FILES := proguard.flags
-LOCAL_CERTIFICATE := platform
-LOCAL_MODULE_TAGS := optional
-LOCAL_PACKAGE_NAME := AntHalService
-
-# Remove all verbose and debug logging when building user.
-ifeq ($(TARGET_BUILD_VARIANT),user)
-    LOCAL_PROGUARD_FLAG_FILES += proguard.nolog.flags
-endif
-
-include $(BUILD_PACKAGE)