Add noexcept to move constructors and assignment operators.

Bug: 116614593
Test: build with WITH_TIDY=1
Change-Id: Ib6ab6a0c3268562376df6125df258dee7a97d5ce
diff --git a/keystore/auth_token_table.h b/keystore/auth_token_table.h
index db60003..4110370 100644
--- a/keystore/auth_token_table.h
+++ b/keystore/auth_token_table.h
@@ -97,9 +97,9 @@
     class Entry {
       public:
         Entry(HardwareAuthToken&& token, time_t current_time);
-        Entry(Entry&& entry) { *this = std::move(entry); }
+        Entry(Entry&& entry) noexcept { *this = std::move(entry); }
 
-        void operator=(Entry&& rhs) {
+        void operator=(Entry&& rhs) noexcept {
             token_ = std::move(rhs.token_);
             time_received_ = rhs.time_received_;
             last_use_ = rhs.last_use_;