Migrate grc blocks from xml to yaml

Convert the blocks using cmdline_converter.py script from
https://gist.githubusercontent.com/haakov/4228ff6a14486641add538483093e86b/raw/c861a840e31182ace2e74f5425e356cb4f8b183a/cmdline_converter.py

Change-Id: Iee5c611a2e100bd2fdf487611a867dc937d8c292
diff --git a/grc/qa_utils/gsm_message_source.block.yml b/grc/qa_utils/gsm_message_source.block.yml
new file mode 100644
index 0000000..abb1800
--- /dev/null
+++ b/grc/qa_utils/gsm_message_source.block.yml
@@ -0,0 +1,39 @@
+# auto-generated by grc.converter
+
+id: gsm_message_source
+label: Message Source
+
+parameters:
+-   id: messages
+    label: Messages
+    dtype: raw
+    default: '["02 04 01 00 00 00 c9 00 00 1d 3c e5 02 00 01 00 15 06 21 00 01 f0
+        2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+
+        "02 04 01 00 00 00 ca 00 00 1d 3c e9 02 00 02 00 15 06 21 00 01 f0 2b 2b 2b
+        2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+
+        "02 04 01 00 00 00 cb 00 00 1d 3d 0e 01 00 00 00 59 06 1a 00 00 00 00 00 00
+        00 00 00 00 00 00 00 00 00 00 ff e5 04 00",
+
+        "02 04 01 00 00 00 cb 00 00 1d 3d 12 02 00 00 00 15 06 21 00 01 f0 2b 2b 2b
+        2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b"]'
+    hide: 'true'
+
+outputs:
+-   domain: message
+    id: msgs
+
+templates:
+    imports: import grgsm
+    make: grgsm.message_source(${messages})
+
+documentation: |-
+    This block is a basic message source for testing purposes.
+
+    It takes a list of strings as input, where each string
+    is a whitespace-separated list of hexadecimal values representing the data bytes of a message including the gsmtap header.
+
+    Such strings can be obtained using the message printer with option "Print GSMTap header"
+
+file_format: 1