Prepares hostapd for use by a wifi HAL vendor APEX

- Allows hostapd AIDL to read from an APEX for config files.
- Creates a cc_defaults with soong config vars for hostapd that
  customized implementations can override.
- Change -DCONFIG_HIDL to -DCONFIG_AIDL

Bug: 205065320
Test: m -j with mac80211_hwsim vendor APEX on Cuttlefish
Test: Connect to wifi and run hotspot
Change-Id: Id9937724a397d74c070a0b176c5ec0c18b71c9d1
diff --git a/hostapd/aidl/Android.bp b/hostapd/aidl/Android.bp
new file mode 100644
index 0000000..3cbccee
--- /dev/null
+++ b/hostapd/aidl/Android.bp
@@ -0,0 +1,48 @@
+// Copyright (C) 2021 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 {
+    default_applicable_licenses: [
+        "external_wpa_supplicant_8_license",
+        "external_wpa_supplicant_8_hostapd_license",
+    ],
+}
+
+cc_library_headers {
+    name: "libhostapd_aidl_headers",
+    export_include_dirs: ["."],
+    soc_specific: true,
+}
+
+cc_library_static {
+    name: "libhostapd_aidl_bp",
+    srcs: ["*.cpp"],
+    defaults: ["hostapd_cflags_defaults"],
+    soc_specific: true,
+    shared_libs: [
+        "android.hardware.wifi.hostapd-V1-ndk",
+        "libbinder_ndk",
+        "libbase",
+        "libutils",
+        "liblog",
+    ],
+    cppflags: [
+        "-Wall",
+        "-Werror",
+    ],
+    header_libs: [
+        "hostapd_headers",
+        "libhostapd_aidl_headers",
+    ],
+}