logd: worst-UID only to preserve a day

Do not invoke worst-UID pruning in the face of other
UIDs logs that are more than a day old, switch to
pruning oldest only.

Change-Id: Icf988b8d5458400a660d0f8e9d2df3f9d9a4c2d9
diff --git a/logd/LogBufferElement.h b/logd/LogBufferElement.h
index 5dabaac..3dcf9d1 100644
--- a/logd/LogBufferElement.h
+++ b/logd/LogBufferElement.h
@@ -48,6 +48,11 @@
 
 class LogBuffer;
 
+#define EXPIRE_HOUR_THRESHOLD 24 // Only expire chatty UID logs to preserve
+                                 // non-chatty UIDs less than this age in hours
+#define EXPIRE_THRESHOLD 4       // A smaller expire count is considered too
+                                 // chatty for the temporal expire messages
+
 class LogBufferElement {
     const log_id_t mLogId;
     const uid_t mUid;