bindings-java : disable flash attention by default

This commit disables flash-attention for the Java binding test so that
the testFullTranscribe test passes.

Without this change the test was failing because the expected output
mismatches after the flash-attention change:
```console
<And so my fellow Americans ask not what your country can do for you ask what you can do for your country.>
but was:
<and so my fellow Americans ask not what your country can do for you ask what you can do for your country>
```

An alternative would also be to update the expected output but it felt
better to keep the same expected output and disable flash-attention and
not just change the expected output to match the new behavior.

Author: danbev

bindings/java/src/main/java/io/github/ggerganov/whispercpp/params/WhisperContextParams.java

@@ -20,7 +20,7 @@ public WhisperContextParams() {
     /** Use GPU for inference (default = true) */
     public CBool use_gpu;
 
-    /** Use flash attention (default = false) */
+    /** Use flash attention (default = true) */
     public CBool flash_attn;
 
     /** CUDA device to use (default = 0) */

bindings/java/src/test/java/io/github/ggerganov/whispercpp/WhisperCppTest.java

@@ -4,6 +4,7 @@
 
 import io.github.ggerganov.whispercpp.bean.WhisperSegment;
 import io.github.ggerganov.whispercpp.params.CBool;
+import io.github.ggerganov.whispercpp.params.WhisperContextParams;
 import io.github.ggerganov.whispercpp.params.WhisperFullParams;
 import io.github.ggerganov.whispercpp.params.WhisperSamplingStrategy;
 import org.junit.jupiter.api.BeforeAll;
@@ -25,7 +26,9 @@ static void init() throws FileNotFoundException {
         //String modelName = "../../models/ggml-tiny.bin";
         String modelName = "../../models/ggml-tiny.en.bin";
         try {
-            whisper.initContext(modelName);
+            WhisperContextParams.ByValue contextParams = whisper.getContextDefaultParams();
+            contextParams.useFlashAttn(false);  // Disable flash attention
+            whisper.initContext(modelName, contextParams);
             //whisper.getFullDefaultParams(WhisperSamplingStrategy.WHISPER_SAMPLING_GREEDY);
             //whisper.getJavaDefaultParams(WhisperSamplingStrategy.WHISPER_SAMPLING_BEAM_SEARCH);
             modelInitialised = true;