idmap2: Remove redundant "using" statements

They are already under the same namespace.

Test: presubmit
Bug: 219872355
Change-Id: Ie09d529bc9d9f690feb5dba16fe174b89a14ee08

cmds/idmap2/Android.bp

@@ -39,6 +39,7 @@ cc_defaults {
         "-modernize-pass-by-value",
         "-modernize-replace-disallow-copy-and-assign-macro",
         "-modernize-return-braced-init-list",
+        "-modernize-use-default-member-init",
         "-modernize-use-equals-default",
         "-modernize-use-nodiscard",
         "-modernize-use-override",

cmds/idmap2/idmap2d/Idmap2Service.cpp

@@ -39,11 +39,9 @@
 #include "idmap2/Result.h"
 #include "idmap2/SysTrace.h"
 
-using android::IPCThreadState;
 using android::base::StringPrintf;
 using android::binder::Status;
 using android::idmap2::BinaryStreamVisitor;
-using android::idmap2::FabricatedOverlay;
 using android::idmap2::FabricatedOverlayContainer;
 using android::idmap2::Idmap;
 using android::idmap2::IdmapHeader;