Add aconfig flag  to control release of unmounting changes

Bug: 402367661
Bug: 318335297
Test: Manual by checking installed flags
Flag: EXEMPT adding flag android.vold.flags.enhance_fuse_unmount
Change-Id: I86847c091d9b08de395e1e6944350b2313004a76
diff --git a/Android.bp b/Android.bp
index f1221eb..bef6471 100644
--- a/Android.bp
+++ b/Android.bp
@@ -158,6 +158,12 @@
         "model/VolumeBase.cpp",
         "model/VolumeEncryption.cpp",
     ],
+    shared_libs: [
+        "server_configurable_flags",
+    ],
+    static_libs: [
+        "vold_flags_c_lib",
+    ],
     product_variables: {
         arc: {
             exclude_srcs: [
@@ -271,3 +277,15 @@
     ],
     path: "binder",
 }
+
+aconfig_declarations {
+    name: "vold_flags",
+    package: "android.vold.flags",
+    srcs: ["aconfig/flags.aconfig"],
+    container: "system",
+}
+
+cc_aconfig_library {
+    name: "vold_flags_c_lib",
+    aconfig_declarations: "vold_flags",
+}
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