Fix ATRACE_TAG redefinition in SysTrace.h

Split SysTrace.h into SysTrace.cpp to avoid defining ATRACE_TAG
in the clients of SysTrace.h

This is in preparation to land aosp/2190022

Test: m
Bug: 161393989
Change-Id: I0ed94c9f66043aa83a59e8042ec9e61ee47db0f2
diff --git a/cmds/idmap2/libidmap2/SysTrace.cpp b/cmds/idmap2/libidmap2/SysTrace.cpp
new file mode 100644
index 0000000..55d45b7
--- /dev/null
+++ b/cmds/idmap2/libidmap2/SysTrace.cpp
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+#define ATRACE_TAG ATRACE_TAG_RRO
+
+#include "idmap2/SysTrace.h"
+
+#ifdef __ANDROID__
+namespace android::idmap2::utils {
+
+ScopedTraceNoStart::~ScopedTraceNoStart() {
+    ATRACE_END();
+};
+
+ScopedTraceMessageHelper::~ScopedTraceMessageHelper() {
+    ATRACE_BEGIN(buffer_.str().c_str());
+}
+
+bool atrace_enabled() {
+    return ATRACE_ENABLED();
+}
+}  // namespace android::idmap2::utils
+#endif