Fix missing ProtoLog viewer config in some tracing instances

We were re-using the same ProtoInputStream across all trace function calls, which meant that only the first tracing instance would get the viewer config and all other tracing instances would be missing the viewer config.

This issue became very common after enabling the AOT protolog config for eng builds.

Change-Id: I05287f64e57ff8ec53e474e368a799fdfd9f62b8
Flag: EXEMPT small bug fix
Bug: 358100425
Test: atest InternalTests:com.android.internal.protolog.PerfettoProtoLogImplTest#handlesConcurrentTracingSessions