Separate the actual trace to pprof conversion

Bug: b/135648427
Change-Id: I275dc329a40ef9d7a1c9fe8c7b9b4891913ee198
diff --git a/Android.bp b/Android.bp
index 7a30101..81856fe 100644
--- a/Android.bp
+++ b/Android.bp
@@ -3892,6 +3892,7 @@
     "src/trace_processor/virtual_destructors.cc",
     "src/trace_processor/window_operator_table.cc",
     "tools/trace_to_text/main.cc",
+    "tools/trace_to_text/pprof_builder.cc",
     "tools/trace_to_text/proto_full_utils.cc",
     "tools/trace_to_text/trace_to_profile.cc",
     "tools/trace_to_text/trace_to_systrace.cc",