[SendTabToSelf] Added metrics to all Android flows

(cherry picked from commit 5d2de4af31e088410ba0e44331363f82d7875901)

Bug: 942177
Change-Id: I2012b3d192a0772a7fe1057ccc582d44b440937c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1648976
Commit-Queue: Tanya Gupta <tgupta@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: Jeffrey Cohen <jeffreycohen@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#667605}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1654388
Reviewed-by: Tanya Gupta <tgupta@chromium.org>
Cr-Commit-Position: refs/branch-heads/3809@{#242}
Cr-Branched-From: d82dec1a818f378c464ba307ddd9c92133eac355-refs/heads/master@{#665002}

• chrome/android/chrome_java_sources.gni[diff]
• chrome/android/java/src/org/chromium/chrome/browser/send_tab_to_self/DevicePickerBottomSheetContent.java[diff]
• chrome/android/java/src/org/chromium/chrome/browser/send_tab_to_self/NotificationManager.java[diff]
• chrome/android/java/src/org/chromium/chrome/browser/send_tab_to_self/SendTabToSelfMetrics.java[Added - diff]
• chrome/android/java/src/org/chromium/chrome/browser/send_tab_to_self/SendTabToSelfShareActivity.java[diff]
• chrome/android/junit/src/org/chromium/chrome/browser/send_tab_to_self/SendTabToSelfShareActivityTest.java[diff]
• tools/metrics/histograms/histograms.xml[diff]