Fix sf trace flag propagation in winscope

Fixes a couple of issues:
- if no flags are set, the configuration will not be send to the proxy.
Fix this by always sending the requested config
- make winscope tracing sync by default as a temp workaround for the
async tracing crashes

Bug: none
Test: toggle composition trace flags from winscope and check trace
Change-Id: I724dcc19309a616d3eb096d966dd40bf00c5d8ed
2 files changed