added .clangd config file. initialized uninitialized variables am: da4f72913f am: 1b00ac25da am: 1fcf426dfb am: c9426b9154

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2205476

Change-Id: Iba5ce54daa2f125022b20e3a9f70f85a5e328ca1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>