Rationalize logging statements across codebase

This fixes up the following problems:
1. Using string concatenation instead of the formatting variant methods.
2. Logging or swallowing exception messages without logging the exception
   itself (this swallows the stack trace).
3. Unnecessary logging on re-thrown exceptions.
4. Unnecessary use of formatting variant methods when not necessary.
5. Complicated logging statements involving significant processing not being
   wrapped inside of a logging level check.
6. Redundant logging both of an exception itself and its message (this is
   unnecessary duplication).
7. Use of the base Logger class instead of our FormattingLogger class.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=182419837

java/google/registry/module/frontend/FrontendServlet.java

@@ -51,12 +51,12 @@ public final class FrontendServlet extends HttpServlet {
                 try {
                   metricReporter.get().stopAsync().awaitTerminated(10, TimeUnit.SECONDS);
                   logger.info("Shut down MetricReporter");
-                } catch (TimeoutException timeoutException) {
-                  logger.severefmt("Failed to stop MetricReporter: %s", timeoutException);
+                } catch (TimeoutException e) {
+                  logger.severe(e, "Failed to stop MetricReporter.");
                 }
               });
     } catch (Exception e) {
-      logger.severefmt(e, "Failed to initialize MetricReporter: %s");
+      logger.severe(e, "Failed to initialize MetricReporter.");
     }
   }