Simplify initialization and add setValue to support parceling

Bug: 197162116
Test: atest libbattery_test

Change-Id: I4278206eab049d714c5278e6b10ba3155e17142f
diff --git a/libs/battery/LongArrayMultiStateCounter.cpp b/libs/battery/LongArrayMultiStateCounter.cpp
index 68e0883..125cfaf 100644
--- a/libs/battery/LongArrayMultiStateCounter.cpp
+++ b/libs/battery/LongArrayMultiStateCounter.cpp
@@ -62,7 +62,7 @@
 template <>
 std::string LongArrayMultiStateCounter::valueToString(const std::vector<uint64_t>& v) const {
     std::stringstream s;
-    s << "{ ";
+    s << "{";
     bool first = true;
     for (uint64_t n : v) {
         if (!first) {