[Java] Update javadoc for publication unblocking when using the Publication.tryClaim.

Author: mjpt777

aeron-client/src/main/java/io/aeron/ExclusivePublication.java

@@ -437,6 +437,8 @@ public long offer(
      * available.
      * <p>
      * <b>Note:</b> This method can only be used for message lengths less than MTU length minus header.
+     * If the claim is held for more than the aeron.publication.unblock.timeout system property then the driver will
+     * assume the publication thread is dead and will unblock the claim thus allowing other threads to make progress.
      * <pre>{@code
      *     final ExclusiveBufferClaim bufferClaim = new ExclusiveBufferClaim();
      *

aeron-client/src/main/java/io/aeron/Publication.java

@@ -417,6 +417,8 @@ public long offer(
      * Once the message has been written then {@link BufferClaim#commit()} should be called thus making it available.
      * <p>
      * <b>Note:</b> This method can only be used for message lengths less than MTU length minus header.
+     * If the claim is held for more than the aeron.publication.unblock.timeout system property then the driver will
+     * assume the publication thread is dead and will unblock the claim thus allowing other threads to make progress.
      * <pre>{@code
      *     final BufferClaim bufferClaim = new BufferClaim(); // Can be stored and reused to avoid allocation
      *