processor: Move ftrace parsing and descriptors to importers/ftrace

In preparation of aosp/1146725

Bug: 141459049
Change-Id: Icbb1379646222aed95c389818195f1f5e44ea919
diff --git a/BUILD b/BUILD
index 3bc3a5d..a2c858d 100644
--- a/BUILD
+++ b/BUILD
@@ -642,8 +642,6 @@
         "src/trace_processor/filtered_row_index.h",
         "src/trace_processor/forwarding_trace_parser.cc",
         "src/trace_processor/forwarding_trace_parser.h",
-        "src/trace_processor/ftrace_descriptors.cc",
-        "src/trace_processor/ftrace_descriptors.h",
         "src/trace_processor/ftrace_utils.cc",
         "src/trace_processor/ftrace_utils.h",
         "src/trace_processor/graphics_event_parser.cc",
@@ -656,6 +654,13 @@
         "src/trace_processor/heap_profile_allocation_table.h",
         "src/trace_processor/heap_profile_tracker.cc",
         "src/trace_processor/heap_profile_tracker.h",
+        "src/trace_processor/importers/ftrace/ftrace_descriptors.cc",
+        "src/trace_processor/importers/ftrace/ftrace_descriptors.h",
+        "src/trace_processor/importers/ftrace/ftrace_module.h",
+        "src/trace_processor/importers/ftrace/ftrace_parser.cc",
+        "src/trace_processor/importers/ftrace/ftrace_parser.h",
+        "src/trace_processor/importers/ftrace/ftrace_tokenizer.cc",
+        "src/trace_processor/importers/ftrace/ftrace_tokenizer.h",
         "src/trace_processor/importers/fuchsia/fuchsia_provider_view.cc",
         "src/trace_processor/importers/fuchsia/fuchsia_provider_view.h",
         "src/trace_processor/importers/fuchsia/fuchsia_trace_parser.cc",
@@ -670,11 +675,6 @@
         "src/trace_processor/importers/json/json_trace_tokenizer.h",
         "src/trace_processor/importers/json/json_trace_utils.cc",
         "src/trace_processor/importers/json/json_trace_utils.h",
-        "src/trace_processor/importers/proto/ftrace_module.h",
-        "src/trace_processor/importers/proto/ftrace_parser.cc",
-        "src/trace_processor/importers/proto/ftrace_parser.h",
-        "src/trace_processor/importers/proto/ftrace_tokenizer.cc",
-        "src/trace_processor/importers/proto/ftrace_tokenizer.h",
         "src/trace_processor/importers/proto/proto_importer_module.h",
         "src/trace_processor/importers/proto/track_event_module.h",
         "src/trace_processor/importers/systrace/systrace_parser.cc",