Update OpenCensus to HEAD (5501a1a) (#32687)

Update to
5501a1a255

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bazel/grpc_deps.bzl

@@ -373,11 +373,11 @@ def grpc_deps():
     if "io_opencensus_cpp" not in native.existing_rules():
         http_archive(
             name = "io_opencensus_cpp",
-            sha256 = "20119a53cc1c140347671ac40650d797567ec63bd3a9f135e17f144fdb36c272",
-            strip_prefix = "opencensus-cpp-3e6aa4c0fb31d2f39a2d38365483599ab50bef6d",
+            sha256 = "46b3b5812c150a21bacf860c2f76fc42b89773ed77ee954c32adeb8593aa2a8e",
+            strip_prefix = "opencensus-cpp-5501a1a255805e0be83a41348bb5f2630d5ed6b3",
             urls = [
-                "https://storage.googleapis.com/grpc-bazel-mirror/github.com/census-instrumentation/opencensus-cpp/archive/3e6aa4c0fb31d2f39a2d38365483599ab50bef6d.tar.gz",
-                "https://github.com/census-instrumentation/opencensus-cpp/archive/3e6aa4c0fb31d2f39a2d38365483599ab50bef6d.tar.gz",
+                "https://storage.googleapis.com/grpc-bazel-mirror/github.com/census-instrumentation/opencensus-cpp/archive/5501a1a255805e0be83a41348bb5f2630d5ed6b3.tar.gz",
+                "https://github.com/census-instrumentation/opencensus-cpp/archive/5501a1a255805e0be83a41348bb5f2630d5ed6b3.tar.gz",
             ],
         )