Make javadoc <p> style guide compliant

This led to confusion for an open source contributor about how to format
code. We don't want to be like, "do as I say, not as I do."

https://google.github.io/styleguide/javaguide.html#s7.1.2-javadoc-paragraphs
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=122589700

java/google/registry/util/AppEngineTimeLimiter.java

@@ -26,22 +26,22 @@ import java.util.concurrent.TimeUnit;
 /**
  * A factory for {@link TimeLimiter} instances that use request threads, which carry the namespace
  * and live only as long as the request that spawned them.
- * <p>
- * It is safe to reuse instances of this class, but there is no benefit in doing so over creating a
- * fresh instance each time.
+ *
+ * <p>It is safe to reuse instances of this class, but there is no benefit in doing so over creating
+ * a fresh instance each time.
  */
 public class AppEngineTimeLimiter {
 
   /**
    * An {@code ExecutorService} that uses a new thread for every task.
-   * <p>
-   * We need to use fresh threads for each request so that we can use App Engine's request threads.
-   * If we cached these threads in a thread pool (and if we were executing on a backend, where there
-   * is no time limit on requests) the caching would cause the thread to keep the task that opened
-   * it alive even after returning an http response, and would also cause the namespace that the
-   * original thread was created in to leak out to later reuses of the thread.
-   * <p>
-   * Since there are no cached resources, this class doesn't have to support being shutdown.
+   *
+   * <p>We need to use fresh threads for each request so that we can use App Engine's request
+   * threads.  If we cached these threads in a thread pool (and if we were executing on a backend,
+   * where there is no time limit on requests) the caching would cause the thread to keep the task
+   * that opened it alive even after returning an http response, and would also cause the namespace
+   * that the original thread was created in to leak out to later reuses of the thread.
+   *
+   * <p>Since there are no cached resources, this class doesn't have to support being shutdown.
    */
   private static class NewRequestThreadExecutorService extends AbstractExecutorService {
 

java/google/registry/util/CollectionUtils.java

@@ -113,9 +113,9 @@ public class CollectionUtils {
 
   /**
    * Turns an empty collection into a null collection.
-   * <p>
-   * This is unwise in the general case (nulls are bad; empties are good) but occasionally needed to
-   * cause JAXB not to emit a field, or to avoid saving something to datastore. The method name
+   *
+   * <p>This is unwise in the general case (nulls are bad; empties are good) but occasionally needed
+   * to cause JAXB not to emit a field, or to avoid saving something to datastore. The method name
    * includes "force" to indicate that you should think twice before using it.
    */
   @Nullable

java/google/registry/util/DateTimeUtils.java

@@ -31,10 +31,10 @@ public class DateTimeUtils {
 
   /**
    * A date in the far future that we can treat as infinity.
-   * <p>
-   * This value is (2^63-1)/1000 rounded down. AppEngine stores dates as 64 bit microseconds, but
-   * Java uses milliseconds, so this is the largest representable date that will survive
-   * a round-trip through the datastore.
+   *
+   * <p>This value is (2^63-1)/1000 rounded down. AppEngine stores dates as 64 bit microseconds, but
+   * Java uses milliseconds, so this is the largest representable date that will survive a
+   * round-trip through the datastore.
    */
   public static final DateTime END_OF_TIME = new DateTime(Long.MAX_VALUE / 1000, DateTimeZone.UTC);
 

java/google/registry/util/X509Utils.java

@@ -53,9 +53,9 @@ public final class X509Utils {
   /**
    * Parse the encoded certificate and return a base64 encoded string (without padding) of the
    * SHA-256 digest of the certificate.
-   * <p>
-   * Note that this must match the method used by the GFE to generate the client certificate hash so
-   * that the two will match when we check against the whitelist.
+   *
+   * <p>Note that this must match the method used by the GFE to generate the client certificate hash
+   * so that the two will match when we check against the whitelist.
    */
   public static String getCertificateHash(X509Certificate cert) {
     try {