Revert D14423742: Use of TraceCompat

Summary:
D14423742 introduced a regression on OSS test_android due to androidx.core.os not being available. I spent some time investigating a fix forward this morning, with no success. Reverting.

Changelog:

[Android] [Changed] - Revert 92f019c

Reviewed By: cpojer

Differential Revision: D14668728

fbshipit-source-id: c7542992805551dc4302626e1536759794efaa82

ReactAndroid/src/main/java/com/facebook/systrace/BUCK

@@ -3,7 +3,6 @@ load("//tools/build_defs/oss:rn_defs.bzl", "rn_android_library")
 rn_android_library(
     name = "systrace",
     srcs = glob(["*.java"]),
-    is_androidx = True,
     visibility = [
         "PUBLIC",
     ],

ReactAndroid/src/main/java/com/facebook/systrace/Systrace.java

@@ -7,7 +7,8 @@
 
 package com.facebook.systrace;
 
-import androidx.core.os.TraceCompat;
+import android.os.Build;
+import android.os.Trace;
 
 /**
  * Systrace stub that mostly does nothing but delegates to Trace for beginning/ending sections.
@@ -54,11 +55,15 @@ public static void traceInstant(
   }
 
   public static void beginSection(long tag, final String sectionName) {
-    TraceCompat.beginSection(sectionName);
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
+      Trace.beginSection(sectionName);
+    }
   }
 
   public static void endSection(long tag) {
-    TraceCompat.endSection();
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
+      Trace.endSection();
+    }
   }
 
   public static void beginAsyncSection(