[sensors] Add explicit [Exposed=Window] to interfaces

The DeviceMotionEventAcceleration and DeviceMotionEventRotationRate
interfaces were missing an explicit [Exposed=Window] attribute. This was
added to the specification in,

https://github.com/w3c/deviceorientation/pull/79

Bug: 792432
Change-Id: I5a185b1d2aa8cb0fc5022dfb80e7188fab0f083d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1773545
Reviewed-by: Tim Volodine <timvolodine@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691323}