8176337: Mark several tests as intermittently failing

Reviewed-by: darcy

jdk/test/java/io/FileInputStream/LargeFileAvailable.java

@@ -24,6 +24,7 @@
 /*
  * @test
  * @bug 6402006 7030573 8011136
+ * @key intermittent
  * @summary Test if available returns correct value when reading
  *          a large file.
  */

jdk/test/java/lang/ProcessBuilder/Basic.java

@@ -28,6 +28,7 @@
  *      6464154 6523983 6206031 4960438 6631352 6631966 6850957 6850958
  *      4947220 7018606 7034570 4244896 5049299 8003488 8054494 8058464
  *      8067796
+ * @key intermittent
  * @summary Basic tests for Process and Environment Variable code
  * @modules java.base/java.lang:open
  * @run main/othervm/timeout=300 Basic

jdk/test/java/nio/channels/FileChannel/LoopingTruncate.java

@@ -24,6 +24,7 @@
 /**
  * @test
  * @bug 8137121 8137230
+ * @key intermittent
  * @summary (fc) Infinite loop FileChannel.truncate
  * @library /lib/testlibrary
  * @build jdk.testlibrary.Utils

jdk/test/java/nio/channels/FileChannel/Transfer.java

@@ -24,6 +24,7 @@
 /* @test
  * @bug 4434723 4482726 4559072 4638365 4795550 5081340 5103988 6253145
  *   6984545
+ * @key intermittent
  * @summary Test FileChannel.transferFrom and transferTo (use -Dseed=X to set PRNG seed)
  * @library ..
  * @library /lib/testlibrary/

jdk/test/java/nio/channels/FileChannel/Transfers.java

@@ -22,6 +22,7 @@
  */
 
 /* @test
+ * @key intermittent
  * @summary Comprehensive test for FileChannel.transfer{From,To}
  * @bug 4708120
  * @author Mark Reinhold

jdk/test/javax/net/ssl/DTLS/CipherSuite.java

@@ -27,6 +27,7 @@
 /*
  * @test
  * @bug 8043758
+ * @key intermittent
  * @summary Datagram Transport Layer Security (DTLS)
  * @modules java.base/sun.security.util
  *          jdk.crypto.ec

jdk/test/sun/security/tools/keytool/DefaultSignatureAlgorithm.java

@@ -24,6 +24,7 @@
 /*
  * @test
  * @bug 8138766
+ * @key intermittent
  * @summary New default -sigalg for keytool
  * @modules java.base/sun.security.tools.keytool
  * @modules jdk.crypto.ec