Move flattened APEX activation logic to apexd.

Also the check that linker configuration should not be updated if APEX
is in updatable state, is removed as now with refactoring of code and its
movement to apex project, that is also needed.

Resolves: https://b.corp.google.com/issues/192838499
Test: Run the AVD Device and check that it boots and run atest
ApexTestCases

Change-Id: I80a94fa0a4145d30546bb34a6d478a20a2881368
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 035038f..7633d9c 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -1305,20 +1305,8 @@
 
     return {};
 }
-
-static bool IsApexUpdatable() {
-    static bool updatable = android::sysprop::ApexProperties::updatable().value_or(false);
-    return updatable;
-}
-
 static Result<void> do_update_linker_config(const BuiltinArguments&) {
-    // If APEX is not updatable, then all APEX information are already included in the first
-    // linker config generation, so there is no need to update linker configuration again.
-    if (IsApexUpdatable()) {
-        return GenerateLinkerConfiguration();
-    }
-
-    return {};
+    return GenerateLinkerConfiguration();
 }
 
 static Result<void> parse_apex_configs() {