Remove CompOS SDK from the prebuilts

This reverts commit 8c216ad7a90d815f5edd000df43a21fc41f9c6a7 and also
remove the prebuilts at once.

In the new design, ART won't need to use CompOS SDK.

Bug: 203231943
Test: prebuilts/runtime/mainline/update.py still works
Change-Id: I3f1adc7efdfc8a0eb4ad302d8c1cc32ca92822a4
9 files changed