Fix volume value and DPE range

 - return 1.0 to the framework, since the effects take over volume
   control
 - fix the range of DPE, go/dpe-oob
 - fix typo

Bug: 303565339
Test: manually test
Change-Id: If18d6115a6223f9f76e205f8128089d9af9d5a1d
Merged-In: If18d6115a6223f9f76e205f8128089d9af9d5a1d