audio: Support 64bit configuration on 32+64bit compatible OS

The default value is 'prefer32', in order to run the hardware audio
service as 64 bit on a 32+64bit OS, please add the content below
into 'device.mk':

SOONG_CONFIG_NAMESPACES += android_hardware_audio
SOONG_CONFIG_android_hardware_audio += \
	run_64bit
SOONG_CONFIG_android_hardware_audio_run_64bit := true

Bug: 205240941
Test: build pass
Signed-off-by: Carter Hsu <carterhsu@google.com>
Change-Id: Ic7632a4f80298721512cd538ce93945b82a9981f

audio/common/all-versions/default/service/Android.bp

@@ -7,17 +7,40 @@ package {
     default_applicable_licenses: ["hardware_interfaces_license"],
 }
 
+soong_config_module_type {
+    name: "android_hardware_audio_config_default",
+    module_type: "cc_defaults",
+    config_namespace: "android_hardware_audio",
+    bool_variables: [
+        "run_64bit",
+    ],
+    properties: ["compile_multilib"],
+}
+
+android_hardware_audio_config_default {
+    name: "android_hardware_audio_config_defaults",
+
+    soong_config_variables: {
+        run_64bit: {
+            conditions_default: {
+                // Prefer 32 bit as the binary must always be installed at the same
+                // location for init to start it and the build system does not support
+                // having two binaries installable to the same location even if they are
+                // not installed in the same build.
+                compile_multilib: "prefer32",
+            },
+            compile_multilib: "64",
+        },
+    },
+}
+
 cc_binary {
     name: "android.hardware.audio.service",
 
     init_rc: ["android.hardware.audio.service.rc"],
     relative_install_path: "hw",
     vendor: true,
-    // Prefer 32 bit as the binary must always be installed at the same
-    // location for init to start it and the build system does not support
-    // having two binaries installable to the same location even if they are
-    // not installed in the same build.
-    compile_multilib: "prefer32",
+
     srcs: ["service.cpp"],
 
     cflags: [
@@ -34,6 +57,10 @@ cc_binary {
         "libutils",
         "libhardware",
     ],
+
+    defaults: [
+        "android_hardware_audio_config_defaults",
+    ],
 }
 
 // Legacy service name, use android.hardware.audio.service instead