Allow first uid in attribution chain as primary field

Test: bit statsd_test:*
Bug: 142108433
Change-Id: I6a2f8e6198765d4205dac95e5f54666496b78808
diff --git a/cmds/statsd/src/state/StateTracker.cpp b/cmds/statsd/src/state/StateTracker.cpp
index ef59c92..3ad21e0 100644
--- a/cmds/statsd/src/state/StateTracker.cpp
+++ b/cmds/statsd/src/state/StateTracker.cpp
@@ -28,10 +28,14 @@
 StateTracker::StateTracker(const int32_t atomId, const util::StateAtomFieldOptions& stateAtomInfo)
     : mAtomId(atomId), mStateField(getSimpleMatcher(atomId, stateAtomInfo.exclusiveField)) {
     // create matcher for each primary field
-    // TODO(tsaichristine): b/142108433 handle when primary field is first uid in chain
-    for (const auto& primary : stateAtomInfo.primaryFields) {
-        Matcher matcher = getSimpleMatcher(atomId, primary);
-        mPrimaryFields.push_back(matcher);
+    for (const auto& primaryField : stateAtomInfo.primaryFields) {
+        if (primaryField == util::FIRST_UID_IN_CHAIN) {
+            Matcher matcher = getFirstUidMatcher(atomId);
+            mPrimaryFields.push_back(matcher);
+        } else {
+            Matcher matcher = getSimpleMatcher(atomId, primaryField);
+            mPrimaryFields.push_back(matcher);
+        }
     }
 
     // TODO(tsaichristine): b/142108433 set default state, reset state, and nesting
diff --git a/cmds/statsd/src/state/StateTracker.h b/cmds/statsd/src/state/StateTracker.h
index 7453370..70f1627 100644
--- a/cmds/statsd/src/state/StateTracker.h
+++ b/cmds/statsd/src/state/StateTracker.h
@@ -72,7 +72,7 @@
 
     int32_t mDefaultState = kStateUnknown;
 
-    int32_t mResetState;
+    int32_t mResetState = kStateUnknown;
 
     // Maps primary key to state value info
     std::unordered_map<HashableDimensionKey, StateValueInfo> mStateMap;