Revert "READ_DROPBOX_DATA permission"

Revert submission 24670896-DropBoxPermission

Reason for revert: DroidMonitor: Potential culprit for Bug 305144053 - verifying through ABTD before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted

Reverted changes: /q/submissionid:24670896-DropBoxPermission

Change-Id: Ieac6a8a63f77aa002672bf4ea9c18ddf0d9a4a23