Add Riju as OWNER in imagecapture/.

Riju is spec editor for ImageCapture and is leading efforts to add new
features both in the spec and in chrome.

Bug: None.
Change-Id: I9c0ac3496d2d867d2c9223842dac2fce63659690
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2160972
Auto-Submit: Rijubrata Bhaumik <rijubrata.bhaumik@intel.com>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#761983}

third_party/blink/renderer/modules/imagecapture/OWNERS

 reillyg@chromium.org
+rijubrata.bhaumik@intel.com
 
 # Original (legacy) owner.
 mcasas@chromium.org