Revert "Fix crash when Background Memory metrics task is scheduled immediately."

This reverts commit 5f4571dc.

Reason for revert: Another metric, TaskStartedNative, is logged incorrectly.

Original change's description:
> Fix crash when Background Memory metrics task is scheduled immediately.
> 
> It is scheduled with a random delay between 0ms and 59999ms. When it is
> exactly 0, the delayed task is actually executed as a regular task,
> and since it is scheduled just before the task that starts native,
> it runs without native, causing a crash.
> 
> Moving recordMetrics() to after native is initialized fixes the issue.
> 
> Bug: 1017130
> Change-Id: Ica5d0a125b93433bd2291a6c73ac30d3fd890aa8
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1880172
> Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
> Reviewed-by: Mohamed Heikal <mheikal@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#709269}

TBR=hnakashima@chromium.org,mheikal@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1017130
Change-Id: Ie5bef0866b02530232aeb383adfaae5feaf6511a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1883044Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709906}

chrome/android/java/src/org/chromium/chrome/browser/background_task_scheduler/NativeBackgroundTask.java

@@ -136,12 +136,12 @@ public abstract class NativeBackgroundTask implements BackgroundTask {
 
         boolean wasInServiceManagerOnlyMode = isNativeLoadedInServiceManagerOnlyMode();
         mRunningInServiceManagerOnlyMode = supportsServiceManagerOnly();
+        recordMetrics();
 
         final BrowserParts parts = new EmptyBrowserParts() {
             @Override
             public void finishNativeInitialization() {
                 PostTask.postTask(UiThreadTaskTraits.DEFAULT, startWithNativeRunnable);
-                recordMetrics();
             }
             @Override
             public boolean startServiceManagerOnly() {