Reverse logic of context tracking enablement from #1927 (#1971)

In this commit it disabled by default and can be enabled via
`RCCL_ENABLE_CONTEXT_TRACKING=1` for both (CDNA, RDNA)
Original PR https://github.com/ROCm/rccl/pull/1927

[ROCm/rccl commit: 00a42c80f3]

projects/rccl/docs/how-to/rccl-usage-tips.rst

@@ -269,11 +269,13 @@ The default allreduce PyTorch benchmark peak bus bandwidth performance is
 ~170 GB/s on a single OAM with ROCm 6.2.4, while the optimized run for CPX on a
 single OAM peaks at ~315 GB/s.
 
-Context tracking on Radeon GPUs
+Context tracking on GPUs
 ----------------------------------------
-Context tracking is disabled on the AMD Instinct™ series of GPUs for better performance but is enabled for Radeon GPUs.
-To disable context tracking for Radeon GPUs, set the following environment variable:
+Context tracking is disabled by default for optimal performance. However, enabling of context tracking can significantly improve performance
+in certain scenarios. To enable context tracking, set the following environment variable:
 
 .. code-block:: shell
 
-   export RCCL_DISABLE_CONTEXT_TRACKING=1
+
+   export RCCL_ENABLE_CONTEXT_TRACKING=1
+