dashboard/app: increase text entity size limit
dashboard/app: increase text entity size limit

Increase text entity size limit from 2MB to 10MB.
In preparation for dumping /proc/lockdep* files in vm.Diagnose.
A typical log file I am getting with lockdep info is ~5MB
which compresses to ~500KB.

xairy/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller