storaged: allow dump window to be less than an hour

This is useful for CTS where we just need dump from last few minutes.

Bug: 34198239
Bug: 34845096
Change-Id: Ic543e7184606f419f8989bf0cb992cd46e48845c
diff --git a/storaged/storaged_uid_monitor.cpp b/storaged/storaged_uid_monitor.cpp
index 2c20dba..3b893b5 100644
--- a/storaged/storaged_uid_monitor.cpp
+++ b/storaged/storaged_uid_monitor.cpp
@@ -150,7 +150,7 @@
 }
 
 std::map<uint64_t, std::vector<struct uid_record>> uid_monitor::dump(
-    int hours, uint64_t threshold, bool force_report)
+    double hours, uint64_t threshold, bool force_report)
 {
     if (force_report) {
         report();
@@ -162,7 +162,7 @@
     uint64_t first_ts = 0;
 
     if (hours != 0) {
-        first_ts = time(NULL) - (uint64_t)hours * HOUR_TO_SEC;
+        first_ts = time(NULL) - hours * HOUR_TO_SEC;
     }
 
     for (auto it = records.lower_bound(first_ts); it != records.end(); ++it) {